back to article Want a more fuel efficient car? Then redesign it – here's how

Cars are mass-produced consumer products sold to users who mostly know very little about them. They are optimised to make a profit for the manufacturer, so low build cost is paramount for most manufacturers – which automatically excludes many design and engineering ideas that would raise efficiency. John Watkinson has been busy …

  1. HKmk23

    A light foot and wheel geometry works wonders

    Excellent article, may I add that making sure the wheels run free (you would be surprised have many cars run around with brakes binding just a little...), Also ensure that the wheels are running in a straight line on the straight and that the geometry is equal on the curves, correct tyre pressures also.

    I get 25mpg from my 5litre V10 Touareg at 130kph and that weighs 2.85 tonnes!

    1. JeffyPoooh
      Pint

      Fig 3 says it all

      One way to improve fuel mileage figures, if that's the ultimate goal, is to move house further from work.

    2. david 12 Silver badge

      Re: A light foot and wheel geometry works wonders

      After working on my own cars and bikes, I was amazed to see a wheel spin, and spin, and spin, and spin, on an upside-down race car. On my cars, you can barely turn the undriven wheels by hand, due to bearing friction, and the bikes were only much better. Evidently race cars have much much much better wheel bearings.

      1. Eddy Ito

        Re: you can barely turn the undriven wheels by hand

        I'm sorry but you've obviously tightened the nut a bit too tight. I've built, and rebuilt, many vehicles starting with a '51 Willy's 4-73 pickup and at no time have I ever had an undriven wheel not spin freely for many revolutions after repacking the bearings and reinstalling the wheel.

        As a rule of thumb, as much as I hate that term, the bearing only need be tight enough to prevent off-axis motion so I'm thinking go a half a turn, depending on where the castle nut lines up with the hole, beyond where it obviously seats but no more or snug it up and back off a half a turn, either way should get you in a reasonable ballpark.

        I'm sure there may be manuals that say tighten to "X" ft-lbs, but that's largely shite if you think about it since there is no way they can know the exact taper of the conical bearing, nominal maybe but exact never. You tell me, what's the derivative of the sine of the bearing angle? Yeah, approximations are ok but certainly not gospel.

        On a similar note, I'll add that the author misses what is to me an obvious point. The wheels, given their contribution to the acceleration of the vehicle - a wheel / tire combination that has a larger portion of the mass on the perimeter is harder to accelerate than an equal mass wheel / tire combination where the mass in concentrated in the center.

        More often than not the latest fad is to have a large diameter, low mass rim paired with a large diameter tire and it doesn't optimize the acceleration since a smaller wheel with a larger sidewall may, actually more often than not, provide a better moment of inertia and therefore less work to accelerate to a given velocity.

        1. DaLo

          Re: you can barely turn the undriven wheels by hand

          It's surprising how many people think a car gets better MPG when going downhill if they go into neutral!

          Leave any modern car in high gear with your foot off the accelerator and it will consume no fuel, in neutral it will need to maintain the engine idling.

          1. passportholder

            Re: you can barely turn the undriven wheels by hand

            I think one exception to that is if you are coating to accelerate down a hill.

          2. Alan Brown Silver badge

            Re: you can barely turn the undriven wheels by hand

            "It's surprising how many people think a car gets better MPG when going downhill if they go into neutral!"

            Depending on the car, slope and engine temp they may be right.

            Using the Torque OBD app, the instant milage changes between overrun and coasting on a few local hills is eye opening (90 vs 180mpg when cold, 180 vs 240mpg when hot). I suspect that modern engines put a small amount of fuel through even on overrun to keep the cat hot (or light it in the first place), even when the manifold pressure is down around -13.5psi.

            There are a bunch of techniques to improve milage. Ripping out weight to the extent shown is a bit radical, but it's probably improved reliability dramatically given my experience of 1960/70s british cars (somewhere along the line, "made in britain" became a warning label)

            Other hacks: lighter/synthetic gearbox/diff oil, ditto on the engine, roller tappets, narrower tyres/higher pressure. The comments on the lights are valid, but they make so little difference that it's not worth bothering with. As for the alternator, dump it entirely - GM proved in the 1950s that an exhaust turbine-driven alternator was a lot more efficient, but had trouble with reliability under heat loads. Belt drives put asymetric pressure on bearings and sap far more energy than could ever be recovered by hacking the regulator circuitry. There are a couple of designs for electrical generation using turbocharger housings - and spinning at 15-25,000 RPM means the entire alternator can be a heck of a lot lighter/simpler.

            1. NullReference Exception

              Re: you can barely turn the undriven wheels by hand

              I don't know about Torque specifically, but a lot of similar tools/apps/devices calculate their mileage estimates based only on speed and the airflow through the engine as registered by the MAF sensor (always assuming an ideal air-fuel mixture.) There will always be some air flow through the engine even if fuel gets cut off, and your app may or may not be taking this into account. If Torque will show you injector pulse width, check that - if it goes to zero, you aren't burning any fuel.

            2. Anonymous Coward
              Anonymous Coward

              Re: you can barely turn the undriven wheels by hand

              "There are a couple of designs for electrical generation using turbocharger housings - and spinning at 15-25,000 RPM means the entire alternator can be a heck of a lot lighter/simpler."

              Nice idea - if your car spends most of its life on the highway. In traffic jams with the engine idling you'll soon find the battery going flat however as the turbo/alternator pack sits there doing virtually nothing.

            3. Vic

              Re: you can barely turn the undriven wheels by hand

              There are a couple of designs for electrical generation using turbocharger housings

              I was playing with a FireStreak missile the other day - that uses a turbo alternator to generate its electrical power, driven from an onboard pressure vessel.

              Of course, a missile doesn't tend to last as long as a car from first ignition to end-of-life...

              Vic.

        2. Peter Simpson 1
          Happy

          Re: you can barely turn the undriven wheels by hand

          You tell me, what's the derivative of the sine of the bearing angle?

          cosine of the bearing angle.

          sin -> cos -> -sin -> -cos

          Clockwise for derivative, CCW for integral. One of the few things in my engineering education that stuck and is very seldom used. But it's there when I need it...like now :-)

          // Have a friend who says the only thing wrong with British cars is the Lucas electrics. Just rip 'em out, he says, and replace them with Delco.

        3. NogginTheNog
          FAIL

          Re: you can barely turn the undriven wheels by hand

          "More often than not the latest fad is to have a large diameter, low mass rim paired with a large diameter tire and it doesn't optimize the acceleration"

          Not only that, they often look SHITE! They look like cart wheels from a distance, and unless you've got decent brakes worth showing off you're just telling the world your car only needs crappy drums to stop!

        4. AJ MacLeod

          @Eddy Ito

          "I'm sorry but you've obviously tightened the nut a bit too tight."

          That's impossible on the vast majority of cars these days as almost all of them use sealed bearing assemblies (or even complete bolt-in hub units) with the preload already fixed and not adjustable in any way. The days of "snugging it down and backing off half a turn" are long gone...

          1. Eddy Ito

            Re: @Eddy Ito

            That may be true but it's still possible on my not quite antique daily driver. Still, a wheel should spin quite freely. Perhaps it's the seals on the newer bearing as I've seen several on capital equipment that were quite heavy initially but the friction usually drops considerably after a bit of running.

    3. werdsmith Silver badge

      Re: A light foot and wheel geometry works wonders

      And brake happy motorists take note, it is very expensive to heat the air behind you by pressing that middle (or left) pedal too much, and too many people do it. There are people that whinge about manufacturer MPG figures being wrong, but never take a look at their own driving style, it is not difficult to get close to, or exceed manufacturer MPG figures in any car.

      As for the author's Jag, I too cannot justify replacing my 7 year old car, because a new one would do no more. It is petrol, but I can drive it to better MPG figures than my diesel colleagues and it just keeps on going through MoTs without needing any work. But, the author's Jag? Something wrong there, I feel that the cost of all the modifications, not to mention time is probably far more than it will ever return of fuel savings. Especially when he could have done a lot better in ££ terms just by getting an LPG conversion.

      1. 9Rune5

        Re: A light foot and wheel geometry works wonders

        Not necessarily a good idea, especially if you live in areas that see lots of salt on the roads come winter time.

        My Saab 9-5 has so far covered a little more than 100000 km in five years.

        This spring I had to replace my rear brake discs due to corrosion. My front discs only required a little brushing on the edges, but had corroded a little bit even there.

        Amount of fuel saved: Negligible. Cost of new brake discs: Quite noticable. Of course, having a bit bigger discs than average plays into the equation too, but having proper stopping power can be a money saver in the end (my dad almost plunged into a Skoda that had decided it was a good idea to stop around a bend).

    4. Anonymous Coward
      Anonymous Coward

      Re: A light foot and wheel geometry works wonders

      >Also ensure that the wheels are running in a straight line on the straight and that the geometry is >equal on the curves, correct tyre pressures also.

      >

      >I get 25mpg from my 5litre V10 Touareg at 130kph and that weighs 2.85 tonnes!

      I would suggest a better way to get better mpg is not drive around in a pointless 2.85 ton tank with the aerodynamics of a barn door and buy a normal car instead. An added bonus is people then won't think you're trying to compensate for a problem in the trouser department.

  2. Anonymous Coward
    Anonymous Coward

    Best car based article yet from El Reg.

    This!

    Was very interesting and pretty practical.

  3. Pen-y-gors

    Depends on assumptions

    "Suppose you drive 5,000 miles (8,046km) a year in a car that does 30mpg and costs say, £205.00 to tax. Fuel and tax are costing you about £1,160. Swap it for a new car that does 40mpg and costs, say, £145 to tax. Fuel and tax are now costing you about £860, a saving of £300 per annum."

    But how many cars these days can only do 30mpg? My 1989 Porsche 944 automatic manages 30mpg! And most new cars should manage a lot more than 40mpg.

    With a more realistic set of assumptions: 12000 miles per year, and buy a new car that does 60mpg, with low emissions...

    Costs of old car: petrol 2360 + 205 tax = £2565

    Costs of new car: fuel 1180 + £20 tax = £1200

    Annual saving = £1365.

    Cost of new car £10K? so paid for completely in 7-8 years, less if you manage to get any trade-in on the old one.

    But of course, if you're talking about a classic car, then you don't buy it based on fuel efficiency - you buy it because you love it, and sod the expense!

    Of course, your mileage may vary. Still an interesting article though.

    1. Anonymous Coward
      Anonymous Coward

      Re: Depends on assumptions

      The disadvantages include modern cars being so hideously complex, that even changing a light* often requires a workshop and workshop tools, and I wait to be convinced of the longevity and long term fuel efficiency of the current crop of TSI type micro-sized engines.

      My neighbour has a 1.0L Focus that, despite spending more time at the Ford Dealership than on her drive, STILL only manages 34MPG average, in a rural, small town environment.

      BTW, has the author written a book or thought of setting up a business to help others do this sort of work?? My MPV only averages 30MPG, but there is no newer equivalent, so anything I can do to improve MPG is eagerly looked at. (Official mpg is 20/38/30); I have been thinking of an engine pre-heater, but they arent cheap.

      *Some Skoda Fabias need the front bumper removing to replace the headlights, and dont talk to me about Renaults.

      1. Pen-y-gors

        Re: Depends on assumptions

        Fair point - I think the solution is to have a cheap, boring, modern, economical, comfortable car for day-to-day use (e.g. deisel Skoda) and then the classic Porsche/Jag/whatever for a few thousand miles of expensive annual motoring that's fun!

      2. Dan delaMare-Lyon

        Re: Depends on assumptions

        Owners forums are a wonderful source of all that is good in the world of motoring and have helped me greatly. There is no way, without the forums, I'd have ever done half of what I have on my car - and it being from the VAG stable, you have to faff about inside in "invisible" space with tools to take the headlights out to change the bulbs - usually losing part of said tool into the bottom of the car in the process. Same with the rear lights where the bolt holding them in place is placed such that the likelihood of you losing the bolt/tool tip/magnetic holder into the bodywork is at its maximum. So much so that it's a standing joke for the apprentices at the dealers to be given these jobs then made to find the missing part which involves taking the back of the car apart...

        That said though, much of what the author quotes has happened with cars these days anyway. Electric power-steering - check. Revised starting systems - check. More advanced cooling systems - Check. Weight reduction - Check. Changed drive ratios - Check - the list goes on and on.

        To go back and apply it to something designed 40 years ago - hats off!

        Very few people actually check their cars between a light telling them to do so - and most only check tyre pressures when they look low - having driven hundreds of miles, maybe even thousands with them low chewing through extra fuel and causing safety problems....

        Now if only there was a solution....oh wait, attended garages....that could catch on! Check oil, water, tyre pressures.....oh well!

        1. Nigel 11

          Re: Depends on assumptions

          Check oil, water, tyre pressures.....oh well!

          The first two ought to look after themselves. I do check, but I've never had to top up either oil or water (in a Seat Leon now 12 years old). Anyone know, is the oil warning stil just a pressure alert, or does it now alert to a low level in the sump as well? (I discovered recently, my car has a low screenwash reservoir alert. Never knew that until I let it run low).

          You can now buy tyre pressure monitors (TPMS) that replace the valve caps and which are interrogated by a remote box in your car. So now, tyre pressures can be checked continuously, which enhances both safety and fuel consumption. The kit costs about £100.

          I can also vouch for Goodyear Efficient Grip Tyres (er something like that) saving fuel. Low rolling resistance. The cost of of fuel saved over the life of a tyre is in the same ballpark as the cost of the tyre, so it's probably not worth fitting one until your existing tyre is worn out. (I treat 3mm of tread as worn out. Wet grip is very signifcantly compromised from there down to the legal limit).

          1. Solmyr ibn Wali Barad

            Re: Depends on assumptions

            "Anyone know, is the oil warning stil just a pressure alert, or does it now alert to a low level in the sump as well?"

            No good rule here. Quite a lot of cars have an oil level sensor these days. But not all. Would be wise to check the user manual on that.

        2. Alan Brown Silver badge

          Re: Depends on assumptions

          "So much so that it's a standing joke for the apprentices at the dealers to be given these jobs then made to find the missing part which involves taking the back of the car apart..."

          A friend and I made up a gooseneck with electromagnet for exactly those situations back in the 80s..A suitably modified boroscope would work better these days - and bear in mind that a strong enough magnet _will_ move the loose nut/part to where you can get at it, even through sheet steel

          1. Anonymous Coward
            Anonymous Coward

            Re: Depends on assumptions

            I've got a VAG car and can change both front and rear lights in minutes. Perhaps it's model specific.

            Worst I had was a Fiat where I could just about contort my wrist to get to the bulbs but couldn't see what I was doing. Took me an hour to get the job done.

            As someone else said pretty much all of the things in the article have already been done on modern cars.

            One thing which did strike me as strange was the water circulation. I've never owned a Jag but the two or three cars I had from the 70s already have a thermally operated valve which prevented water going through the radiator until the car was up to temperature.

            I wonder if the author has also considered plastic replacement bonnet/boot, lower weight carpeting, more modern lighter weight sound proofing material, lighter exhaust parts, exhaust wrapping, cold air intake etc.

      3. John Brown (no body) Silver badge

        Re: Depends on assumptions

        "Some Skoda Fabias need the front bumper removing to replace the headlights,"

        As does a Kia C'eed. But in my case it's a company car so not my problem.

      4. Voland's right hand Silver badge

        Re: Depends on assumptions

        Engine pre-heaters are cheap. If you use the right pre-heater:

        http://www.wolverineheater.com/

        10 x more economical than a coolant fluid-preheater, you do not need to run it all night to have a usable engine in the morning. An hour or two is enough. Come in both 220V and 120V versions.

        I would definitely advise putting a full front underside shield on the car though to avoid stone chip damage to the filter over time.

        1. MJI Silver badge

          Re: Depends on assumptions

          I bit my oil filter would not get stone chipped.

          It is changed from the top!

      5. werdsmith Silver badge

        Re: Depends on assumptions

        "STILL only manages 34MPG average, in a rural, small town environment."

        Bad driving.

      6. Back to school

        Re: Depends on assumptions

        I have a 1.0T focus, typically get low 40's running around town 2-3 mile journeys and up to 50 on an A road run. It's not supposed to be super economical like the 800kg NA micro cars, it's supposed to be more economical than the 1.6NA it replaces ... and in that it succeeds.

        As for bumpers .. my other car is an elderly but strong diesel passat, it takes about 3 minutes to remove the bumper, hardly the end of the world, when a bulb went a few years back I replaced them all while the bumper was off. Fairly trivial if you can use a screw driver.

      7. Soruk

        Re: Depends on assumptions

        > *Some Skoda Fabias need the front bumper removing to replace the headlights, and dont talk to me about Renaults.

        I can change the bulbs in my Renault Modus - perhaps the fact my hands are relatively small means I can actually do it.

        1. Dabooka Silver badge

          Re: Depends on assumptions

          "I can change the bulbs in my Renault Modus - perhaps the fact my hands are relatively small means I can actually do it."

          Rear light clusters are a pain though, unless you know the knack and a brave enough to stick a screwdriver where it doesn't belong!

          1. Stacy

            Re: Depends on assumptions

            You mean Volvo are still in the minority of making (front) bulbs easier? I pull a tent peg looking thing out of my headlight cluster and it pops out so you can change the bulbs. Makes it easy to swing the beam when I come to the UK as well.

            Mind you. There isn't even access to the rear cluster! Not without removing the interior lining and soundproofing anyway!

      8. Alan Brown Silver badge

        Re: Depends on assumptions

        "that even changing a light* often requires a workshop and workshop tools,"

        ISTR some EU design rule changes a couple of years back mandating that bulb changes must be doable at the roadside. The result was to hasten the move to leds, as they're not regarded as a user serviceable part.

    2. a pressbutton

      Re: Depends on assumptions

      what modern car does less than 30 mpg

      - alfa 147 2.0 in bristol!

      (changed for a bmw 120d that does 48mpg on the same trip)

      1. Paul Smith

        Re: Depends on assumptions

        bet you wish you still had the Alpha...

    3. Anonymous Coward
      Anonymous Coward

      Re: Depends on assumptions

      Using a car for work, promise of 47mpg by manufacturer, reality 35pmg.

      Average yearly milage 18,000 and 47 tankfuls of fuel a year.

      Bought small diesel van

      Manufacturer claims 67mpg, reality 59mpg and 32 tankfuls of fuel a year.

      Saving 15 tanks of fuel or approximately £825 a year.

      1. Solmyr ibn Wali Barad

        Re: Depends on assumptions

        "Bought small diesel van /.../ Saving 15 tanks of fuel or approximately £825 a year."

        Great. That is, if the diesel engine is a good one, and you don't have to blow the money on maintenance. I don't seem to trust those small highly tuned diesels yet. It's a bit of gamble.

    4. launcap Silver badge
      Stop

      Re: Depends on assumptions

      > But how many cars these days can only do 30mpg?

      Mine - 1.8L Honda FRV (Automatic). It might be my driving style (surely not!) but around town I get 25 MPG. Open motorway gets me to about 33..

      I'd love to still be able to run a manual (likewise still be able to ride a motorbike) but arthritis in various joints cuts that idea out.

  4. AndrueC Silver badge
    Thumb Up

    Best tip to save fuel when driving: DWB (Driving Without Brakes). It's easier if you have a manual but I manage it with an automatic that has a torque converter. Not only will it save a lot of fuel but it makes you a safer driver and adds a lot of interest to driving. To do it well you have to be paying attention and become very good at anticipating what other road users are going to do.

    My instructor (30 years ago) told me "Brakes are for stopping and correcting your mistakes". I've always stuck by that advice. It doesn't mean that you use gear changes instead of braking. It means never needing to slow faster than you can achieve by lifting off.

    1. Pen-y-gors

      Advanced Motoring

      Yep - that's what they teach on the Institute of Advanced Motorists courses - anticipation is very important, looking a long way ahead. Things like adjusting speed gently at roundabouts so that you can just keep going and slot into a gap rather than stopping and starting.

      The courses are well worth doing - they may have changed a bit in the last 20 years, but they really improve your driving, even if (like everyone is) you know you're a "Good Driver". You go out in your car with an 'Observer' (experienced, trained member) who doesn't tell you what to do, but just makes comments and suggestions. When you're ready you do the test (two hours with a trained Police driver - seriously stressful!) - I think they now call it the Skill for Life course and the whole thing costs £149 - which is a real bargain.

      1. Anonymous Coward
        Anonymous Coward

        Re: Advanced Motoring

        Just be aware that when you don't touch your breaks your break lights don't come on!

        If you're not careful you'll have someone to close behind you running into you!

        1. JeffyPoooh
          Pint

          Re: Advanced Motoring

          "breaks" is not the correct word.

        2. Shades

          Re: Advanced Motoring

          "If you're not careful you'll have someone to close behind you running into you!"

          Then the inconsiderate arseholes better have insurance or I'll hunt them down and they'll end up paying for it in other ways!

          1. Nigel 11

            Re: Advanced Motoring

            "If you're not careful you'll have someone to close behind you running into you!"

            Best thing to do with a lunatic drving on your rear bumper is to let him get in front of you as soon as possible. A genuine case of whiplash isn't worth any amount of damages, and that's the least that might happen. But also note, *gentle* pressure on your brake pedal will illuminate your brake lights without actually engaging your brakes. If there's a potential hazard developing ahead you should transfer your foot to the brake pedal and illuminate your brake lights (which is correct, you will be slowing down slightly because your throttle is closed).

            1. Anonymous Coward
              Anonymous Coward

              Re: Advanced Motoring

              I completely agree Nigel.

            2. Anonymous Coward
              Anonymous Coward

              Re: Advanced Motoring

              This is a good point, Nigel 11, and reminds me (reference my own post above) that when as a poor student I was hypermiling my T100 bike, I fitted an extra brake light switch to the front brake lever (on the handlebars) so that when I was using the (phenomenal) engine braking I could move the lever just enough to turn the lights on. In those days most bikes only had a switch on the rear brake, and we were taught to apply front brake first, so rear ends by the dopey weren't that uncommon.

        3. Anonymous Coward
          Anonymous Coward

          @ ChrisZ Re: Advanced Motoring

          "Just be aware that when you don't touch your breaks your break lights don't come on!

          If you're not careful you'll have someone to close behind you running into you!"

          The fact you said this makes me wonder if you are one of those people on the motorway, or dual carriageway, that sits within half a second to a second behind the person in front of you. Whereas *brake*-lights are a vital indicator of what is going on, if you are relying on those brake lights to stop you running into the person in front of you just because they lift off the throttle at those speeds, then i seriously hope you lose your license in other ways before you kill someone because *you* are dangerous.

          1. Anonymous Coward
            Anonymous Coward

            Re: @ ChrisZ Advanced Motoring

            Wow 17 down votes and a lot of assumption about my driving.

            No I'm not one of those idiots. I stay well back!

            I'm just warning others there are others out there that are just potential accidents waiting to happen. Do an advanced course like AIM and they'll give you the same warning! I believe they call it defensive driving to always assume everyone else outside of your own vehicle might an idiot.

            It doesn't matter if it's there insurance that's going to cover it. You'll still have a mark on your insurance for five years, and you'll still be without your own vehicle, and have a whole s**t load of paperwork to work through. After many telephone calls and sitting on hold with a bit of luck you'll get your excess back.

            Well caught on the spelling. I blame tiredness - one of those dev deadline weeks. (As a result my car hasn't moved for over a week!)

            1. Anonymous Coward
              Anonymous Coward

              Re: @ ChrisZ Advanced Motoring

              their^ for the grammar pedants. There's plenty more mistakes where those came from.

            2. Major N

              Re: @ ChrisZ Advanced Motoring

              "I believe they call it defensive driving to always assume everyone else outside of your own vehicle might an idiot."

              Having spent years on a motorcycle, I live by that creed, albeit in the slightly elongated form "Assume everyone else on the road who is an idiot who is trying to kill you"

              Riding a motorcycle makes you much more aware of what is going on in the road ahead of you; you're typically looking further ahead, aware of that person coming to the junction who may just pull out in front of you, or that car parked near an intersection so visibility of both parties at said intersection cannot see each other.

              My pet hate is people in these ridiculously long vehicles who actually nose out into traffic just so they can see; I dread to think how many cyclists have been caught out by these... (though don't get me started on cyclists; red lights are for all road users, including you, don't blindly cycle through them like you own the road!). Is there a competition between german car manufacturers to a) sell to the biggest douches; b) see how close they can egt to getting the driver sitting in the boot?

          2. Dabooka Silver badge
            Headmaster

            Re: @ ChrisZ Advanced Motoring

            "i seriously hope you lose your license..."

            Licence?

        4. Matt Bryant Silver badge
          WTF?

          Re: Mr ChriZ Re: Advanced Motoring

          ".....If you're not careful you'll have someone to close behind you running into you!" Why the down votes? This is exactly what happened to me - I used engine-braking and the Buy My Wares driver behind me, despite a good gap, hit my car hard enough to do £3k of damage and give my passenger and me whiplash, his excuse being "But I didn't see you brake."

          1. tojb
            Boffin

            Re: Mr ChriZ Advanced Motoring

            Surprising number of people have zero or poor 3D vision. It is quite OK to get/keep a driving licence with one eye, so being merely crosseyed or having a neurological impairment to depth perception goes by the board.

            1. Dr Dan Holdsworth

              Re: Mr ChriZ Advanced Motoring

              The numbers of drivers with poor vision are, in my experience, dwarfed by the numbers of drivers who are just plain stupid. A dearth of police patrol cars (especially unmarked ones) to remove such morons from the roads is also a contributary factor here; in times past bad driving habits such as aggressive tailgating at speed would have been spotted and punished; these days the idiots simply get away with it.

              1. Alan Brown Silver badge

                Re: Mr ChriZ Advanced Motoring

                "in times past bad driving habits such as aggressive tailgating at speed would have been spotted and punished; these days the idiots simply get away with it."

                I suspect that the rise of the dash/rear cam will help curb this issue a bit. They're mandatory equipment in Russia and will probably become so everywhere.

                A couple of people commented that aggressive tailgaters back right off when they clock the camera peering at them through the rear window and I was bemused when they were proved right.

              2. Vic

                Re: Mr ChriZ Advanced Motoring

                The numbers of drivers with poor vision are, in my experience, dwarfed by the numbers of drivers who are just plain stupid.

                Your point about the nuber of crap drivers is well made - but I think you underestimate the number of drivers with poor eyesight...

                Vic.

          2. Alan Brown Silver badge

            Re: Mr ChriZ Advanced Motoring

            "But I didn't see you brake."

            He probably wouldn't have seen you brake anyway. A decent driver isn't soley focussed on the car in front, (s)he's looking 12-20 seconds down the road to see what the traffic's doing and adjust accordingly.

            I'm looking forward to self-driving cars. It gives a chance to seriously increase the requirements for getting a driving license.

            By the way, what's the deal with the advanced driver's course in the UK coming with an INCREASE in driver premiums? (I checked. It's true)

            1. LucreLout

              Re: Mr ChriZ Advanced Motoring

              "By the way, what's the deal with the advanced driver's course in the UK coming with an INCREASE in driver premiums? (I checked. It's true)"

              Mine lower my premiums by about £30 per year. Some insurers wanted to rate higher on it due to the likely higher speed at which I'd be driving based on the increased number of overtakes I'd be pulling.

              Going through their membership broker this year saved me close to 50% of my premium though. Sadly next year they'll have a challenge due to a dappy housewife failing to see the brightly coloured and well illuminated car stopped at the give way, and attempting to punt it out infront of the oncoming motorbike.

          3. Jonathan Richards 1 Silver badge
            Go

            Brake lights -> deceleration lights

            In this day of the electronically controlled car, and low energy LED lighting, perhaps we should have deceleration lights instead of brake lights - if the engine management system says your speed is decreasing, light the warning, or maybe even make the warning intensity proportional to the actual deceleration. Yeah, yeah: one more thing to go wrong!

        5. Anonymous Coward
          Anonymous Coward

          Re: Advanced Motoring

          Totally agree with Mr ChriZ (amazed at the downvotes) when he was suggesting you are aware of it and that at least touching your brakes to show those behind that you are slowing down can be useful.

          If you do a motorbike CBT or a defensive driving course saying "well it was the other person's fault so I'm okay". On a motorbike, someone else's fault even if you are blameless results in serious injury and death so showing your brake light when slowing even when using engine braking is expected.

          To go in to my workplace - I am on a 60mph road with plenty of undulation and turns and I am on an uphill section when I turn left. I could easily slow rapidly with engine braking before turning but as there is a roundabout a little further on drivers behind assume that I am indicating left for the roundabout. Without early and progressive braking (showing lights) I would risk being rear-ended on numerous occasions (a few staff have been).

          Having my car written off on a motorway from a rear end shunt into me (after I stopped as a car in front had a single vehicle incident) means that I am all to aware that thinking "the inconsiderate arseholes better have insurance or I'll hunt them down..." is just idiotic and is not a reason to just think that as long as you are driving well there is nothing you can do to minimise the risks of other's bad driving - having to deal with the repercussions, or even serious injury is just not worth it.

          1. Anonymous Coward
            Anonymous Coward

            @ Chrisz Re: Advanced Motoring

            Kudos for replying and explaining your post.

            I think the downvotes are mainly the context of your comment coming across as "You should brake because that is how other drivers know to slow down" as opposed to "No braking means that the indication of slowing down is now lost and dependent on the driver behind you being aware in time".

            Subtle difference but the context changes from "You should brake" to "Brake lights are a good indication and can only help". But hey, as you say, you are on a deadline....

            The driver following should always be aware, but that same Police Motorcycle Roadcraft book I mentioned earlier does discuss, in detail, the use of using the brake lights as an indicator - which is easy to do on a motorcycle off the front lever and I use myself.

            So have an upvote in apology to my, admittedly, angry retort.

            1. Anonymous Coward
              Pint

              Re: @ Chrisz Advanced Motoring

              No worries. Apology accepted! One upvote in return. Context is often hard to find in such short spans of text. Especially when written by bleary eyed developers...

        6. Alan Brown Silver badge

          Re: Advanced Motoring

          "Just be aware that when you don't touch your breaks your break lights don't come on!"

          You're also decelerating a lot more slowly.

          "If you're not careful you'll have someone to close behind you running into you!"

          In which case they were 1: following too close and 2: not paying attention

          There's a rule about 2 second following distance for a reason (it's expressed in metre per km/h or yards per mph, but it translates exactly to 2 seconds) and it's not to allow twats in fiestas to pull into your safety gap at 90mph.

      2. Anonymous Coward
        Anonymous Coward

        Re: Advanced Motoring

        " When you're ready you do the test (two hours with a trained Police driver - seriously stressful!) "

        Not to the same level but I did this for a council minibus test so I could assist with Duke Of Edinburgh training. Completely agree on the stressful part! Very informative though. I'm a strong believer that everyone should have a retest every 5 years.

    2. Anonymous Coward
      Anonymous Coward

      DWB

      As a student we used to play this game with motorcycles. It isn't possible in London unless you wish to be killed by van drivers, but in the country it may still be possible. In 1970 I used to try to get as much of the distance from home to university as possible without touching the brakes; my favourite was a certain hill where if my T100 was doing 70 at a certain point and I backed off the throttle, it would just hit 30 on the calibrated speedo as I hit the 30 limit.

      I did home to Newcastle (260 miles) on a 3 gallon tankful up the A1, and averaged about 80mpg.

      The point? Well, I think the author is wrong. Modern cars have engines which would have completely awed us in 1970. A city car may not have the acceleration of a typical 1970 500cc bike, but it has roughly equally good fuel consumption, amazing reliability, and much better performance than the average 1970 car. As for Jaguars, well, I remember our engineering director suggesting that if anyone would like to borrow his and write it off, he wouldn't be found ungrateful. (George Buehler in his book on yacht design comments somewhere that a correctly maintained Lister engine is unstoppable and asks how the country that produced the Lister could also produce the Jaguar.)

      The features that he describes as part of his upgrade are par for the course for even small, cheap cars nowadays. Of course people who like classic Jaguars are not going to be seen dead in a Golf, let alone a Toyota of any description, but I'd rather have all those upgrades designed with suitable reliability and hazard analysis by a load of German or Japanese PhDs than one man, no matter how gifted.

      1. Anonymous Coward
        Anonymous Coward

        Re: DWB

        Still do it now. In fact, Anticipating what is going on in front and behind you, matching and anticipating speeds without having to correct it with brakes is, IIRC, known as Speed Awareness in the Motorcycle Roadcraft: The Police Riders Manual.

        But I disagree on your conclusion. The upgrades that seem to be installed are fairly practical and in themselves designed by engineers before being integrated. Far better that an older car is kept going because of the amount of energy taken to create it in the first place.

        Also, modern cars are designed, yes, then built to a price more exacting now. It used to be that a lot of items were vastly overengineered because you included a factor of safety based on manufacturing techniques at the time. Now manufacturing is is very good indeed and things are built more exacting, but tolerances being what they are, and mishaps, you still get failures. Look at all the recalls you get en-mass! Also, modern cars now change more rapidly than they used to, redesigns more constant, even within a same model run. When things break, and they will, getting those parts to keep it on the road is going to be a ball ache, yet alone being within a home mechanics ability, thus shooting the bill for repair up several times in time at a dealership making the car, well, uneconomical to repair well before its time.

        No, sorry, keeping older cars going, as long as practical and not a deathtrap, is sensible. The current view of cars being like mobile phones and changing every few years for a newer model is just nuts.

        1. Anonymous Coward
          Anonymous Coward

          Re: DWB

          Several things.

          First, the overengineering in the past meant that things were heavier, but it was necessary because of the lack of material control. Your old car may have big heavy suspension arms but that isn't going to help if one of them has a load of slag in it and decides to fracture entering a pot hole.

          Second, I wonder how well you can recall the motoring past. The difference then was that recalls weren't efficient so you tended to find out about design faults when they happened to you. If they were even admitted to.

          Third, redesigns were indeed constant and it wasn't unusual to find that the same model had a variety of different parts which might not be well documented, so you went in for a new water pump and then had to wait days because, yes, you had a water pump that wasn't in stock and it was different enough from the other one that the hoses wouldn't fit or the pulley was wrong. There might be a list of which serial numbers had which mod if you were lucky, but with British manufacturing skills it was common to have considerable undocumented overlap around a switchover point.

          I don't mind a minority of mechanically apt people keeping old cars on the road at all, but in those days too many people did their own maintenance who had the mechanical aptitude of the average two toed sloth, and it showed. I didn't actually realise this until I moved out of vehicle R&D and discovered that no, the majority of the population don't take a clutch change as a way of making Sunday less boring. But it wasn't nice to think that a lot of those cars out there had some very dubious running gear. The roads are an awful lot safer than they were in the 1970s, and one reason is that we don't have so many home mechanics.

          Now I'm retired I confess part of me wouldn't mind a suitable old car to play with - an aircooled 911 for preference - but the spousal resistance is rather high and I really need the room in the garage for other things. And it would only be practical because of the two boringly reliable modern cars that provide daily transport.

          1. LucreLout

            Re: DWB

            "The roads are an awful lot safer than they were in the 1970s, and one reason is that we don't have so many home mechanics."

            Sorry, but I'm going to have to ask politely if you have a citation for that or if its just an opinion?

            I'm a home mechanic, and have been for the past 20 years. I know my limits well enough, and am prepared to spend any amount of time to get the job done right. I spend more time studying car mechanics than most dealership trained mechanics will (Hilliers being a good start, but not the end of the journey) and I have no time or profit pressure to force the pace of the job.

            I've had some truly awful workmanship from apparently trained professionals - the kind of standard that makes graduate code look good! The modern mechanic seems to be at a loss if the computer can't tell them what sensor is broken or where specifically the fault may lie. Old fashioned diagnostics, with a little experience, will often come up trumps even with newer stuff.

            Everyone tends to assume their area of expertise is harder to master than it really is. I probably have more experience on cars than a trained professional in their third year of work. Not that I would claim mastery of car mechanics, more the level of an apprentice, but my family ride around in my car that I work on. My incentives to keep it safely are a little higher than my local garage.

            1. Kiwi
              Thumb Up

              Re: DWB

              I'm a home mechanic, and have been for the past 20 years. I know my limits well enough, and am prepared to spend any amount of time to get the job done right.

              Much the same. Classic bikes are my favourites, and I seem to fall in love for bikes that have very hard-to-find parts.

              But I was lucky. A chance meeting in a library more than 20yrs ago led to a 20yr friendship with a guy who could literally add "Rocket Scientist" to his list of skills (which I found out after he sadly passed a couple of years back) but was simply an awesome engineer. So, thanks to him, I learned hugely valuable (and all-but-dead) skills in making tools and parts. I pride myself on being able to fabricate parts and tools as needed (assuming I have the necessary tools and materials stock available).

              I've had some truly awful workmanship from apparently trained professionals - the kind of standard that makes graduate code look good!

              I had to laugh a bit at a friend's mis-fortunes recently.A few months back he had a part of his steering mechanism replaced by a professional, picking his car up well after the professional firm closed for the night. One hair-raising drive home and he was at my door asking me to re-work it. Steering wheel was only some 70-odd degrees out of alignment.

              Last week he had his front brake pads replaced by a "specialist". They now owe him a considerable amount of $$$$ for car repairs because said "specialist" forgot to tighten up the calipers. made quite a mess when he started to brake from motorway speeds, and the calipers came undone. This guy is my best friend and I love him to bits. I would've made absolutely certain that the car was put back together properly. Don't give a damn about the car, I'm a motorcyclist through-and-through and have a passionate dislike of cages - but my friend likes his car, and that's more valuable to me than my desire to see all cars melted down (preferably by firing them (and many of their owners) into the sun!).

              You hit it right on the head with :

              My incentives to keep it safely are a little higher than my local garage.

              Mine are different, but as valuable. If I have a passenger on my bike then they're someone I value far more than the hunk of steel under us (much as I love the bike). If I work on a car, it's because the person is someone I am willing to give that amount of time and sweat to.

            2. Trygve Henriksen

              Re: Home mechanics...

              I had my 1998 Berlingo (1.4i) in for an engine replacement...

              (My fault, sloppy maintenance)

              The replacement was from a 1997...

              The garage first tried to use the ECU from the 1998, then when they realised it wouldn't work with the injectors on the 1997, they tried to swap over the injectors. (No good. Different physical size)

              All because they didn't want to swap out the ECU...

              (The Berlingo didn't connect the ECU and BSI until 2000, when they did a big overhaul of the electronics. So no reprogramming anywhere to do this job)

              On an earlier car of mine, the instrument panel had no lights after they swapped the speedo cable.

              I think I prefer to do the work myself from now...

              1. SEDT

                Re: Home mechanics...

                Re: Home mechanics...

                I had my 1998 Berlingo (1.4i) in for an engine replacement...

                (My fault, sloppy maintenance)

                I think I prefer to do the work myself from now...

                Have you read your post?

            3. Vic

              Re: DWB

              I'm a home mechanic, and have been for the past 20 years.

              I attempted to stop being a home mechanic some 20 years ago - but I keep discovering that the "professionals" have enormous competency issues.

              The last one hit us last year - the VW garage charged my missus some £800 for work to fix a fault - and didn't fix it. They then quoted a further £2500 for the nexst components they intended to change. The problem was clearly an interconnect problem[1] - so I fixed it in about half an hour with no components needed...

              Vic.

              [1] This seems to be an issue with modern VWs - I've seen quite a few reports of the same thing happening. They're cheapskating on the strain relief to save a few pennies, and causing the car to be seriously unreliable as a result.

      2. Alan Brown Silver badge

        Re: DWB

        "George Buehler in his book on yacht design comments somewhere that a correctly maintained Lister engine is unstoppable and asks how the country that produced the Lister could also produce the Jaguar."

        Amen.Those and Mirlees: I had to do daily maintenance on a pair of 300kW 12 cylinder Mirlees diesel generators at one point., They were a thing of awe and beauty when running. Donkey engine providing the juice and air to get them started was a small Lister. They were all 60 years old when scrapped and still ran perfectly.

        1. Trygve Henriksen

          Re: Lister and mirlees diesels...

          I remember an anecdote a friend told me.

          A buddy of his had bought a 1970s fishing boat, and was rebuilding it to live in.

          The SABB (No, not the Sweedish SAAB) diesel looked as it had never been serviced, so he searched around and found plans and parts lists, then called the factory and tried to order a full service kit,(gaskets, bearings, injector, the works).

          The factory spokesman refused to sell him more than a few gaskets, because "There's no way that engine needs a rebuild yet!"

          (If you build an engine to be used as the sole propulsion on a boat destined for the North Atlantic, you tend to err on the side of solidity)

    3. Voland's right hand Silver badge

      DWB - Seconded

      2.5 l Isuzu Rodeo Denver.

      Binary driving (my wife) - sub-30 mpg

      DWB (me) - 37-42 mpg which for a 2 metric ton truck is very reasonable.

    4. Robigus

      Careful drivings means ....

      Farnborough airport to Wolverhampton in 5th gear. 1990's 525 petrol.

      Feather the throttle and anticipate - 40mpg is possible.

    5. Robigus

      Careful drivings means ....

      Farnborough airport to Wolverhampton in 5th gear. 1990's 525 petrol.

      Feather the throttle and anticipate - 40mpg is possible. And yes, I am aware the the load at lower rpm's is relatively inefficient and I should have dropped a couple of gears occasionally, but where's the anecdote in that?

    6. Vic

      My instructor (30 years ago) told me "Brakes are for stopping and correcting your mistakes".

      They're also for increasing performance - but that, of course, will cost you in increased fuel consumption :-(

      Vic.

  5. ZSn

    Cruise control

    Though it may ruin the drive for committed drivers for long distances the most efficiency is cruise control. In my diesel MPV (with the cross-section of a bus) I've managed 5.3l/100 km (54mpg?) with a full load. The way that fuel efficiency varies with speed means that picking a speed and sticking to it (traffic permitting) makes a big difference.

    1. AndrueC Silver badge
      Thumb Up

      Re: Cruise control

      Though it may ruin the drive for committed drivers for long distances the most efficiency is cruise control.

      That may depend on the implementation. I've never really tested it but the CC on my Jazz doesn't fill me with confidence in that respect. It's fine on the flat but going up inclines it lets the speed drop quite a lot (2 or 3mph) before putting the clog down(*) and accelerating to 2 or 3mph above target. Worse still it often seems to start accelerating just before the brow of the hill then it lifts off when it realises it's over shooting in.I do use it but only on motorways and long stretches of A-road that I know are free of upward inclines.

      (*)Although to be fair it is supposed to be better to accelerate 'sharply' rather than barely tickling the accelerator. It's more the way it so often has to lift off and engine brake at the brow of a hill that bothers me.

      1. Kevin Johnston

        Re: Cruise control

        The poor timing of your CC is a classic example of the diffence that extra inputs can make to predictive actions. You can see the brow of the hill approaching but the car cannot.

        It has been said by people who know about these things that a really good driver can out-perfomr ABS as well, but we are talking about properly good drivers as in licensed race/rally type people.

        As the article notes, a lot of the systems in cars both ancient and modern are average at best but hold to the 'good enough' theory of engineering. You could make it better but it would cost more unless you wait until next decade when a new thrugglewasher will be invented.

        The one part which did catch my eye was the digitial wiring loom. As far as I am aware even the latest eco-warrior cars have central control boxes and long copper runs. At the best part of 60lb of weight saved from changing to a digital loom in his project this is an appreciable saving and if taken with changing to LED lighting then I could see this being a nice little earner for some Auto-Electric shops.

        1. xenny

          Re: Cruise control

          ABS was outlawed in F1 as a performance aid, which tells me that the best drivers can't outperform it on dry and presumably wet tarmac. Outperforming it in snow however is essentially impossible.

          1. JeffyPoooh
            Pint

            Re: Cruise control

            "Outperforming [ABS] in snow however is essentially impossible."

            My Mercedes thankfully provides a clever override to ABS. While slowly descending an icy hill, I can press the brake pedal a bit harder to intentionally lock up the wheels (feature, not a bug). This gives my studded tires a second to dig into the icy surface to scrub off speed caused by the downward slippery slope. Of course steering is more or less useless with the wheels locked, so one must pump the brakes manually with a period of several seconds (based on vehicle movements while skidding).

            Normal ABS pumping is too many Hz and provides very little braking action under these conditions, while the hill slope keeps adding speed. Normal ABS can't keep the speed under control; speed caused by slope. The override is very useful as it allows one to give the brake on time more duration so the studs have time to dig in and grip.

            You're probably right about snow, but damp ice on a moderately steep hill is about a thousand times more challenging. Snow is fun. With 4Matic AWD and four Nokian studded tyres, I can make full throttle starts in snow to frighten nearby SUVs, as they typically are equipped with poor 4-season tyres and can't keep up. Snow is fun. Ice is scary.

          2. Nigel 11

            Re: Cruise control

            ABS ... Outperforming it in snow however is essentially impossible.

            ??

            My experience of ABS on show at mercifully very low speed was alarming. Basically, it refused to let me stop at all (on a slight downhill gradient and a very slippery road)

            Later, with ABS disengaged, I established that stopping was possible, though only by controlling a low-speed skid.

            Guess it was dangerous either way.

            1. Phil O'Sophical Silver badge

              Re: Cruise control

              Later, with ABS disengaged

              I'm curious about what car that was? A switch to disengage traction control systems is standard, but I've never seen a modern car that allows you to turn off the ABS.

              1. Nigel 11

                Re: Cruise control

                My 2002 Seat Leon (VW Golf platform). It wasn't really a planned experiment. I tried to stop outside my folks house on snow with ice underneath (after a drive which started nasty and turmed nightmare), the brakes refused to stop the car, so I continued to the bottom of the hill at about walking pace, around the block (uphill was OK), and second time round with a button pressed which I vaguely remembered disabled the ABS and which I'd never found a use for until then or since. Second time I slithered to a halt in about the right place and the ABS didn't kick. I was probably going even slower that time. It was all a bit scary.

            2. SEDT

              Re: Cruise control

              This 'not being able to outperform ABS in snow' is puzzeling me.

              Time was that Audi fitted an ABS off button, specifically for use in snow. The thinking being that locked wheels will collect the snow in a wedge in front of the wheel, thereby slowing you down.

          3. LucreLout

            Re: Cruise control

            "ABS was outlawed in F1 as a performance aid, which tells me that the best drivers can't outperform it on dry and presumably wet tarmac. Outperforming it in snow however is essentially impossible."

            Depends on the system. I had a Renault Megan hatch courtesy car about 10 years ago. The ABS was fine. Then I drove it up north to my folks, and found that trying to brake gently in the snow, the ABS kept disengaging the brakes such that I was unable to slow for the turning I needed. I drove on to find a safe place to stop, pulled the ABS pump fuse, and turned around for a second attempt. The car stopped much faster without the ABS, which simply couldn't cope with snow. As soon as I left the frozen lands of my clan, I reinstalled the fuse, and all was well again.

        2. Naughtyhorse

          Re: Cruise control

          I have long been surprised about the loom thing. As student, back in the 80's I recall being dragged out to a presentation by Ford's on 'the future of motoring-ing-ing-ing' or somesuch, that made exactly this case (indeed they even had a pair of looms for a sierra that graphically demonstrated the differences). Saved weight, Reduced cost, Reduced manufacturing complexity, and improved reliability. I have been patiently waiting for 35 years for this to appear! (file under jet-packs and having 3 pills for dinner).

          Of course these days you could eliminate the control harness and use bluetooth :-)

          Oh, BTW... put me down for one of them new thrugglewashers, my old one is covered in clag, i have tried fettling it, but it's not the same.

          1. Jan 0

            Re: Cruise control back in the 80s

            @Naughtyhorse

            I remember how flush windows and smooth aerodynamic wheels were going to transform our fuel consumption in the 1980s. I'm still waiting for them!

            I also remember the amazing fuel consumption of a drastically overgeared Ford Anglia that I drove in the 1970s. It had been fitted with an engine and differential from a much bigger Ford, maybe a Consul? However, by the time I got it it had reverted to a bog standard Anglia engine with, in effect, a massive overdrive. Luckily I lived in mostly flat Suffolk, because first gear wouldn't pull the skin off a rice pudding. Overtaking required highly advanced planning, but was possible with a long run. Given time it would cruise at a respectable speed, but stopping for petrol stations became a novelty. I can't remember the actual mpg that I got, but I do remember being astonished.

            1. Anonymous Coward
              Anonymous Coward

              Re: Cruise control back in the 80s

              It was called the Audi 100 2.2.

              I regularly cruised up/down the M5 at 100 mph and turned in over 40mpg; back then as a callow youth I had an extremely heavy foot, so got nowhere near the 1200 miles per tank that was possible (best I managed was 900 ish)..

              After a couple of years, Audi stupidly bored it out to 2.3L and the mpg plummeted to barely 30.

              We also then got saddled with catalytic converters which robbed our engines of a 3rd of their power and fuel efficiency..

              1. adam 40 Silver badge

                and giving us all asthma

                didn't you know - platinum residues not only coat our streets but our lungs too.

                Platinum is a potent asthma-inducing allergen.

            2. SEDT

              Re: Cruise control back in the 80s

              You don't need to wait for flush windows, just look at pretty much any car out there

        3. david 12 Silver badge

          Re: Cruise control

          >The poor timing of your [Cruise Control] is a classic example of the difference that extra inputs can make ... You can see the brow of the hill approaching but the car cannot.

          My CC doesn't work correctly with the car in automatic on a positive grade.

          I think that the poor timing on my CC on my GM Cruze is a classic example of a poor product made to a price. Back when people paid extra to get CC on expensive models, I don't think anyone would have paid for this. I certainly would not. It is noticeably worse than any cruise control I've had before. It is 'acceptable' as a 'free' feature of the base model, but it doesn't work as a cruise control except on the flat.

          It doesn't work on hills. I turn the CC off for hills. I have to use the accelerator to control the vehicle speed, because the CC doesn't. It lets the car get far too slow, shifts down a gear, then accelerates up hill to well over the speed limit. And, as a matter of policy, the local police like to do speed checks on up-hill straights, where you don't have any excuse for being over the speed limit.

          1. Anonymous Coward
            Anonymous Coward

            Re: Cruise control

            I have tried several CC cars onthe M4/M5 (Malvern to Heathrow and back usually), and I can reliably get better MPG than any of the systems, often by 15-20%.

        4. Vic

          Re: Cruise control

          It has been said by people who know about these things that a really good driver can out-perfomr ABS

          That's been said by people who "believe" they know about such thnigs - but it's wrong - exept in the loose-surface conditions where locking the wheels is preferable.

          An ABS unit has individual control over the calipers - a driver does not. The ABS unit is more effective, even if the driver can react as rapidly as the electronics[1].

          Vic.

          [1] He can't...

      2. ZSn

        Re: Cruise control

        Well that's true. cruise control is only useful is applied sensibly. Near me there are some stonking hills where it works. It's the shallow inclines it tends to fail on. I tried to test it out on a shallow downhill and in the wrong gear/speed the car accelerates to get to the speed (120 kph) then overshoots the fuel cutout kicks in, the diesel engine creates a huge braking effect and then it tries to accelerate. The resultant jarring on the order of about 0.5 - 1 Hz is enough to shake the change loose from the tray beside me.

        On a side note, will someone at el-reg please disable that 'Dancing Jesus' animation, it's driving me crackers!

        1. This post has been deleted by its author

        2. Kiwi

          Re: Cruise control

          On a side note, will someone at el-reg please disable that 'Dancing Jesus' animation, it's driving me crackers!

          I'm a great fan of the Real Jesus (tm), and was thanking Him profusely for AdBlock (right-click annoying animation, AdBlock -> Block image...) when I was able to consign it permanently to /dev/nul on my system :)

          Things like that are the reason AdBlock is around. It's quite jarring when I work on a machine without AB and see a page loaded with ads..

    2. Nigel 11

      Re: Cruise control

      Cruise control is deadly for fuel efficiency on a motorway with hills. Better to maintain the same throttle setting up the hill, and let the car's speed naturally drop from 70 to 65 or 60 rarely even less. It's up to you whether to catch up the odd minutes on the downhill bits by letting the car reach an illegal 80, or save more fuel by easing off.

      A further aid to fuel efficiency I've never seen on a car would be an airspeed indicator. 60 mph into a 20mph headwind is 80mph as far as drag is concerned. I once worried that something was going wrong with my car's engine, when I got unusually low fuel efficiency on 60 miles of M1. Until I watched the weather forecast, and realised how much of a headwind I'd been driving into. It was probably the equivalent of doing the trip at 95mph on a calm day!

      1. Solmyr ibn Wali Barad

        Re: Cruise control

        "A further aid to fuel efficiency I've never seen on a car would be an airspeed indicator. "

        Well, it would inform the driver about lower-than-expected efficiency, but there's bugger all it can do for improving it. Nor can the driver, actually. Turning around and going in the opposite direction is hardly the solution.

        1. Nigel 11

          Re: Cruise control

          Airspeed indicator:

          "Well, it would inform the driver about lower-than-expected efficiency, but there's bugger all it can do for improving it. Nor can the driver, actually. Turning around and going in the opposite direction is hardly the solution."

          Slowing down may or may not be preferable to spending ££ extra maintaining 70mph. If you had the airspeed information you could make an informed choice between travel time and journey cost (and not worry over an mpg figure ordinarily suggesting engine trouble).

      2. Phil O'Sophical Silver badge
        Flame

        Re: Cruise control

        Better to maintain the same throttle setting up the hill, and let the car's speed naturally drop from 70 to 65 or 60 rarely even less.

        I've driven behind you. Fscking infuriating, either I slow down to keep a safety gap, or I pull out to overtake, just as you decide to accelerate back to 70 on the dowhill. If you can't maintain a constant speed in motorway traffic get a bus pass.

        1. Nigel 11

          Re: Cruise control

          Unlikely you've been driving behind me, unless you expect to do 70mph all the way in the inside lane (in which case, good luck with the HGVs). I'm not a member of CLOG and I do actually give consideration to the traffic behind me. I also don't let my speed drop below that of the HGV behind me, out of common courtesy to a poor sod whose speed is limited to 56mph by law and technology, and who is expected to make deliveries precisely on time. Forcing him into the middle lane to overtake at a tiny delta-V ... that would be crazy. He has enough trouble with the more fully loaded HGVs that can't maintain 56mph up the hills. And HGVs overtaking other HGVs while being prevented from going over 56mph, that's what *really* slows down the traffic on M-ways.

          1. Alan Brown Silver badge

            Re: Cruise control

            "HGVs overtaking other HGVs while being prevented from going over 56mph, that's what *really* slows down the traffic on M-ways."

            Or HGVs in all three lanes (illegal, but happens regularly)

            I like the dutch approach. If there are 2 lanes in each direction, HGVs are prohibited from overtaking - if caught (and they WILL catch, as they have cameras all along those stretches), the driver gets pulled over a few km up the road (regular occurrance between R'dam and A'dam with french drivers who didn't give a shit about the law).

          2. SEDT

            Re: Cruise control

            Nope. the motorways would flow much more efficiently without the middle lane ers, jumpy brake users, and twats in cars doing less that the 56mph that trucks are limited to

          3. Vic

            Re: Cruise control

            And HGVs overtaking other HGVs while being prevented from going over 56mph, that's what *really* slows down the traffic on M-ways.

            Nope. What *really* slows down a motorway is people failing to use the acceleration/deceleration lanes.

            Joining the motorway at low speed causes vast amounts of braking behind you - as does slowing down in the carriageway before you exit...

            Vic.

        2. MJI Silver badge

          Re: Cruise control - maintaning speed

          Last two cars were built without cruise but added trivially. One was stalk and software, the other was a few switches.

          Cruise should be free or at most £50.

          Maintaining speeds.

          I used to own a tuned old hatch with some rally components, very little weight and a three figure power output. The biggest engine version would hassle contemporary super cars.

          On the motorway I would keep to around 80, now hills were fun, I could keep my speed up the steepest going past the repmobiles, but they were so eager to pass me back on the down hills, simply due to car age. (Did not happen with newer cars) This would happen again and again. Actually it was a great car to identify knobs, and it even raised smiles from traffic police.

      3. SEDT

        Re: Cruise control

        Drivers like this, who don't maintain a reasonably consistent speed on motorways, are a danger

  6. bill 36

    Had several Jaguars

    The last one being a 3.2 litre V8 which i loved. The guy i sold it to had it converted to run LPG. Without going into the ins and outs of that conversion, the car then returned the equivalent of 42 MPG when calculating the cost per mile of dual fuel.

    LPG was switched in on motorway cruising usually.

    But the car i regret selling was a 1990 3.6 XJS 4 speed auto. Always returned about 27 MPG on a motorway run, if you kept the right foot light.

    1. JeffyPoooh
      Pint

      Mercedes E class saloon has many of these ideas...

      Aluminininnium bonnet, wings, boot lid. Flat aero panel under engine. Simplified power distribution with CAN-bus controlled switch boxes scattered about. Controllable engine pulleys. It still weighs two tons. Cd supposedly 0.26, which is good, and very noticeable how it slips through the air seemingly effortlessly.

      23 MPG (Imperial gallon) daily driven normally (like I stole it). Or 33 MPG if I hypermile it down the highway. What's that? +45% by driving style and route? The most important weight to remove are your heavy boots.

  7. herman Silver badge

    Fuse wire

    I apreciate that aluminium is lighter than copper, but the high positive temperature coefficient of copper is an important safety point. Aluminium doesn't take kindly to being overloaded and once burning, it cannot be extinguished easily, so this car is in danger of going up in smoke one day.

    1. petur

      Re: Fuse wire

      And I think it's best to use some properly shielded cable for the control signal, not ribbon cable.

    2. Chris Holford
      Boffin

      Re: Fuse wire

      Alumin(i)um has a slightly higher temperature coefficient of resistance than copper!

      http://hyperphysics.phy-astr.gsu.edu/hbase/tables/rstiv.html

      (most pure metals have a value of roughly 0.004/degreeCelsius)

    3. Richard 12 Silver badge
      Flame

      Re: Fuse wire

      Aside from that, copper is considerably more ductile than aluminium, and much easier to properly terminate the ends - a simple crimp will easily cold-weld onto copper, but can shatter aluminium.

      High-current aluminium terminations require careful preparation work (worse than MICC for $deity's sake) as you have to strip the insulating corrosion off, then terminate properly before it corrodes again.

      Thus aluminium is a very, very bad choice for anything that vibrates a lot, or anything that needs a lot of high-current connections because those connections will fail over time, leading to further heating losses, failures, and in the worst cases, fires.

      Once burning, aluminium is effectively impossible to extinguish - adding water will cause a hydrogen explosion, you can only use halon-type or CO2, and once extinguished you must cool the metal very quickly or it will re-ignite.

      In industrial electrics aluminium is specifically prohibited by many insurers and equipment manufacturers.

      In the home, many insurers charge a high premium if you have aluminium wiring due to the increased fire risk.

      There is a reason why car manufacturers still use the more expensive copper.

      1. Naughtyhorse

        Re: copper v ali

        Im not too sure about some of the points you make.

        Crimp connections work perfectly well on ali-ali. It has to be clean (as does copper) as far as power is concerned to properly connect to copper you need bi-metalic terminals. you can cut corners and use heavily tinned ones, but it's not the same.

        As for high current vibration prone connections.... have you ever noticed overhead lines? you know the ones waving about in the air, carrying hundreds of amps, with a worst case mechanical load of a few tons, and a 40 year service interval?

        The key phrase in the OP is weight for weight. In terms of what the article is trying to achieve using ali achieves nothing other than a bigger, stiffer wire.

        1. Richard 12 Silver badge

          Re: copper v ali

          Overhead power lines don't vibrate at all unless there's a particularly nasty earthquake - they swing in the wind, but that's borne by the articulated hangers.

          Aluminium wire (with steel core) is used as a cost-saving measure - it's cheaper per metre and lighter so fewer towers are needed.

          The towers don't vibrate, the terminations are very few and done by well-trained experts so it is a good fit.

          However, car engines vibrate continually, as does everything in a car, there are a lot of terminations and the guy doing them is an enthusiast, not an expert.

          I don't think you've ever seen a high current aluminium connection, or the wire sizes needed for it - aluminium wire is pretty bulky, presenting some tricky problems if you care about long-term stability and safety.

          For example, an efficient car starter motor draws about 80-100 Amps. (A cheap one could draw considerably more).

          1. Naughtyhorse

            Re: copper v ali

            Overhead line suffer (significant) aolean vibration if the tension on the line is much above 20% UTS of the wire.

            this vibration has an amplitude of a few 10's of mm and a wavelength in the order of a few m, with a frequency of the order of 10hz. (the actual sums are horror stories Eigen this and Reynolds that) - quite hard to see from the ground, but easy to spot when a line that should last 40 years fails in 6 months.

            the also gallop - huge low frequency ocillations couple of m in amplitude, and 10's to 100's in wavelength.

            We can (sort of) design out aolean but galloping is more problematic

            ASCR (steel core) wires are sooooo 1970, it's all AAAC - All Aluminium Alloy Conductor (except for the HTLS types, but thay are still rare-ish ) these days. ACSR was not used to save cost. the alloys of ali to do the job did not exist. As soon as they did, we used them. Grid has/had a massive restring program to replace all the quad zebra lines (ACSR) with triple Aurucaria (AAAC) - you may notice as you drive round, some overhead lines have 3 wires per phase and skinny insulators, some have 2 or 4 wires and big ol' porcelain or glass insulators

            towers are under tension, anything under tension vibrates

            terminations on OHL's occur twice per phase (4 times if you count the non-tension joints of the jumpers) at every angle in the line - typically every few km, often less

            (i'll not pass comment on either the training or expertise of my linesmen :-D)

            If you consider the implications of the point above, you will see that in fact I do have some experience with high current terminations. 100A into a starter motor is not going to keep me up at night considering I work on 3.5kA UHV terminations by day (potentially 60kA under fault for a few seconds). In reality it's just like any other electro/mechanical connection. you need to keep things clean, and use the correct tools... correctly

            If you read my op you will not I did point out that using ali just made the wire harder to use - thicker and stiffer (we sometimes used copper conductors in distribution too-it's a nightmare - but that's all about tension, so does not apply here) the resistance per unit length & mass ratios are very similar, but LME prices make ali preferred, but that's only important if you are buying of tons of the stuff at a time.

      2. JeffyPoooh
        Pint

        Re: Fuse wire

        "...those connections will fail over time..."

        Perhaps Jaguar owners would consider that situation to be perfectly normal.

        1. Neil Barnes Silver badge

          Re: Fuse wire

          Beware Lucas, the prince of darkness...

          With regard to Petur's comment regarding screening; yes, if one were to design something using canbus perhaps (though a twisted balanced drive would remove the need in most cases) but for a rewired old Jag, where you're more likely just to be replicating the existing 12vDC signal with a driver or relay at the far end, you're still looking at very low frequency 12v signals. I'd have *no* worries about using ribbon cable, given adequate cable support at the ends to prevent the cable suffering from vibration issues.

          1. Alan J. Wylie

            Re: Fuse wire

            One thing not mentioned - use 24 or 48 volts, rather than 12V. Of course, all your electrical equipment: radio, lights, etc. needs changing or adapting, but your alternator, starter motor and a lot of cable all become a lot lighter.

            The old army air portable Land-Rovers run off 24V

            Almost impossible to retro-fit to an old vehicle, but previous proposals for a voltage of about 40 to 48 volts are being resurrected.

            http://en.wikipedia.org/wiki/42-volt_electrical_system

            http://ae-plus.com/news/audi-charges-up-to-48v-electrical-architecture

            1. JeffyPoooh
              Pint

              Re: Fuse wire

              "...use 24 or 48 volts, rather than 12V."

              Hopefully one doesn't end up with four car batteries in series.

              1. Anonymous Coward
                Anonymous Coward

                Re: Fuse wire

                Hopefully one doesn't end up with four car batteries in series.

                Why not? A standard battery is 6 cells in series. Where's the problem with using 12 or 24 smaller ones?

              2. Nigel 11

                Re: Fuse wire

                "...use 24 or 48 volts, rather than 12V."

                Hopefully one doesn't end up with four car batteries in series.

                Basically, yes. Smaller cells, more thereof. If it ever becomes mainstream you'd have one 24V or 48V batttery containing twice or four times as many cells. For a prototype you'd just use four batteries each a quarter the size of a usual car battery.

                I think it's more likely that Lead-Acid gets replaced by Lithium or NiMH to save weight. A fuel-injected car rarely if ever needs churning to start it. If it hasn't fired in two seconds it almost certainly won't have started twenty seconds later. So a battery with less energy capacity but equal peak current capacity would be fine. Especially if it's better in the cold than lead-acid. Note: this for conventional autos. Hybrids, regenerative braking may make the case for same size or larger batteries.

                1. MJI Silver badge

                  Re: Fuse wire - EFI churning

                  Unless a sensor is starting on its way out, had to crank a bit when the crank sensor started to fail, and I needed recovery in the middle of a postal strike!

                  After the strike fitted the new sensor, perfect.

            2. Alan Brown Silver badge

              Re: Fuse wire

              "Almost impossible to retro-fit to an old vehicle, but previous proposals for a voltage of about 40 to 48 volts are being resurrected."

              Given most EV and Hybrids run around 600V for the traction battery, pretty much any voltage is possible if you put your mind to it.

    4. Naughtyhorse

      Re: Fuse wire

      that's what fuses are for.

      1. Anonymous Coward
        Anonymous Coward

        Re: Fuse wire

        Could I, as someone who has done some serious research into fusing, tell you that the characteristics of fuses are designed for copper wire with conventional insulation, and they would have to be redesigned for aluminium - assuming suitable alloys and bimetal systems can be found? It took years for ISO to harmonise the current designs of vehicle fuses.

        Circuit breakers are a possibility but they have problems with high currents and low voltages.

        1. Solmyr ibn Wali Barad

          Re: Fuse wire

          "Circuit breakers are a possibility but they have problems with high currents and low voltages."

          Pretty much the same story as with relays - susceptible to arcing, electrophoresis, and other wonders of electrochemistry. They'd have to be hermetical and gold-plated in order to work. And probably kill the weight advantage gained from Al* wires.

          1. Naughtyhorse

            Re: Fuse wire

            or even worse... full of SF6

    5. Nigel 11

      Re: Fuse wire

      Aluminium wire will melt long before it catches fire. AFAIK it's only finely powdered aluminium that can sustain a fire (in air) at all.

      So no safety issue. In datacomms (well, telephones) they tried using aluminium in place of copper and found the real drawback: that the IDC connections in street junction boxes oxidised, and became noisy or worse. They went back to using copper. (Now, some cheap cat-5e cable is CCA - Copper Coated Aluminium. I anticipate troubles a decade hence, for the folks using it). With 12V DC power, I guess the corrosion / oxidation issue might result in lights etc. becoming permanently disconnected while the car was parked out in the wet. Or maybe it's been solved.

  8. b166er

    What if you reskinned the doors, wings, bonnet and boot with carbon-fibre? That bonnet alone must weigh a tonne.

    Also those bumpers look damn heavy and I bet the headlight glass is 2 inches thick :)

    Keep the seats though. One can go TOO far!

    1. Tony Haines

      I was thinking he'd whop the seats because racecar.

    2. Wilseus

      I used to own a Citroen BX and many body panels on that were plastic, including the bonnet. I think the whole car weighed only about 800 Kg. Mine was a 60 bhp diesel, was very good on MPG and was quite nippy. I never drove one of the 160 bhp 16v ones but they must have gone like stink!

      1. J P

        Was the BX the one where after a few thousand units they went back to steel bonnets because of production costs - cue urban myth of proud new owners demonstrating how the plastic bonnet just bounces back when you thump it/sit on it/whack it with a hammer..?

  9. Anonymous John

    There's nothing wrong with the Flintstones' car design.

    http://en.wikipedia.org/wiki/La_Jamais_Contente

    1. DropBear

      Interesting link. I find it astonishing that someone clearly caring enough about aerodynamics to make the body rocket-shaped then proceeded to leave the rest of the chassis and the whole driver out in the wind.

      1. Solmyr ibn Wali Barad

        @DropBear

        "someone clearly caring enough about aerodynamics to make the body rocket-shaped then proceeded to leave the rest of the chassis and the whole driver out in the wind."

        It was in 1899. Aerodynamics wasn't very well understood back then. And 'common sense' might have been somewhat different to ours.

        This Tatra from 1930's was a major breakthrough in aerodynamics:

        http://en.wikipedia.org/wiki/Tatra_77

  10. Anonymous Coward
    Anonymous Coward

    The figures speak, but....

    I had a Range Rover 3.5 V8 auto for some years, which I loved dearly. It returned 18.6mpg over the years I had it, dropping to a worst of 12mpg in deep winter snow, along with frequent stopping to pull lesser cars from snowdrifts. The best was just over 25 mpg. This was achieved on a run from Winchester to Birmingham (the old Networks shows) with four hefty techies on board, on a hot summer's day, air con on full blast, and a fastish motorway run all the way. I concluded that the engine was being run inefficiently when you tried lighter loads, etc, and that it actually preferred to be dong some hard work, but otherwise have never been able to understand that result.

    (PS - This Rangie was the cause of the most delightful bit of English I've heard. I was planning to fit a stainless "sports" exhaust system, which apparently improved fuel consumption, but was concerned that the V8 would roar, when I preferred understatement. I phone Rimmer Bros, and asked about any change of exhaust tone. The bloke thought for a moment and said, "No, it's not louder, just a little more..... urgent." I thought that was a delightful way of describing it, meaningless and poetically meaningful at the same time. He was right too.)

  11. Martin an gof Silver badge
    Unhappy

    LED lighting

    I understand their efficiency and, as the owner of a Renault Modus where you can't change some of the front lamps without taking the battery out or the wing off I do understand the appeal of never having to replace them, but LED lights are - aside from inconsiderate drivers - probably the thing that most annoys me on the roads these days. Rear light clusters which combine side and brake lights by pulse-width modulating the LEDs are really distracting and I often find that my attention is in the wrong place, or that I have a trail of red dashes across my vision when I'm trying to drive carefully.

    Some manufacturers use a much higher refresh rate than others which does reduce the effect, but... grrr...

    Oh, and don't get me started on over-bright and over-white LED "driving lights" at the front which are constantly on (thanks to some regulation or other) and are not really a problem in daylight or in the night, but are an absolute menace at dawn and dusk.

    M.

    1. MJI Silver badge

      Re: LED lighting

      I agree those PWM rear lights are horrific. Sometimes you cannot even work out which car they are on.

      I detest those driving lights too, At dusk as bad as main beam

      1. Kevin Johnston

        Re: LED lighting

        Ah, that's because the regulations quote wattage and not lux/lumens/candelas per m2.

        This means your 7 watts for a side light which gives you an incandesant bulb like a glow-worm allows you some LEDs which almost outperform halogen headlamps. Certainly the 50 Watt GU10 bulbs at home have been replaced with LEDs of the same brightness but rated at 5 watts

        Always thought this was something which needed some attention.

        1. Alan Brown Silver badge

          Re: LED lighting

          "Ah, that's because the regulations quote wattage and not lux/lumens/candelas per m2."

          There are definitely lumen limits in there, the problem is that the eye's perception of brightness isn't linear, vs what a photometer shows (the eye is at least 10 times more sensitive to green than red as a f'instance)

    2. J P

      Re: LED lighting

      As an occasional cyclist, LED lights on cars are a pain. I can cheerfully cycle to the station just after dawn with no lights on across the golf course, through the village, seeing and being seen... right up to the outskirts of town, where there's traffic, and every other car is blinding us all with LEDs. If I didn't have a set of unpleasantly bright LED lamps on the bike I'd be effectively invisible. I'm not convinced that an illuminations arms race is the best solution?

  12. Anonymous Coward
    Anonymous Coward

    Interesting article but I can't help feeling that if the author really cared about saving energy on their transport they would do away with the Jag and just buy something else. However you cut it the Jag isn't going to be a fuel efficient vehicle without replacing so much of it that it stops being a Jag.

    Personally, I think the Government could really help out with transport efficiency with one fairly simple change. Let us own an electric car for free. Force the insurance companies to make a policy covering a oil powered car also cover an electric vehicle if the oil powered car is parked on the drive. Why? A lot of driving is just to and from work or to the shops and back which could easily be done by an electric car right now but everyone needs an oil powered car for those longer trips. It's probably just about economical to buy a cheap electric car as a run around but you'd make a massive loss having to insure (and in the future tax) it as well.

    1. MJI Silver badge

      Better to keep an existing car running than waste resources making another

  13. xyz

    Much as I loved the article

    I've got a Musubishi Shogun that drinks deisel so I need all the help I can get. Thanks for the tips.

    HOWEVER...hypermiling is the most selfish, dangerous form of driving I have ever come across. Some smug git sitting on a motorway more concerned about his MPG than his and other people's safety or the road conditions or anything else really. His Hypermilerness might be doing OK, but every other road user is having to pay for his economy by getting round him, so you get artics bunching up behind him, then having to move en masse into the middle lane, which throws the MLOC into the outside lane which causes Mr.Salesman to anchor his beemer and as a result everyone else wastes more fuel, just because Mr. Beardy wants to get off on the fact he did 50mpg or whatever. Death to hypermilers

    1. fruitoftheloon
      FAIL

      Re: Much as I loved the article

      Xyz,

      Err what? I get +34 mpg from a diesel Jeep, prior to which the best we got for a 2.2 diesel s-max was 47mpg.

      Paying attention to ones' fuel consumption (at or near the speed limit) does not necessarily require driving like a selfish tw%t.

      It requires a not inconsiderable amount of concentration to pre-empt other drivers lane and speed changes; methinks smoother driving is also appreciated by my passengers too!

      Plus the money saved on fuel can be put to a much better use on arrival (beer).

      Something to think about!!

      J

    2. werdsmith Silver badge

      Re: Much as I loved the article

      " His Hypermilerness might be doing OK, but every other road user is having to pay for his economy by getting round him"

      Nah, these are people that are sanctimonious about speed, nothing to do with MPG. If you are driving for high MPG you more often than not find that other people are getting in your way forcing unnecessary braking, and it is not slow driving that helps, it's smooth and think-ahead driving.

      Fast foot-down drivers that haven't considered the next junction really don't help, because they haven't worked out ahead how they are going to proceed, and they GET IN THE WAY.

      1. MJI Silver badge

        Chasing lockup

        Actually if you are trying to hypermile an auto you will be doing this a lot, chasing lock up top.

        Most autos I have driven lock up around 50, so if you are following a car and they are desparately trying to drive at 50 rather than 45 - they are trying to hypermile a traditional auto.

        It can make quite a bit of difference in economy.

    3. Conor Turton

      Re: Much as I loved the article

      I do hypermiling, I stick to the speed limit wherever possible. A lot of the time on the motorway whilst hypermiling it means I'm in L3 passing everyone else.

      Hypermiling =/= driving slowly.

      1. Dr Dan Holdsworth

        Re: Much as I loved the article

        Same here.

        On a regular commute of about 40 miles motorway, 20 miles of city driving per day in a 2 litre Avensis diesel, I get about 48 mpg. My normal motorway driving technique is to get the vehicle to 70 and stick on the cruise control at 70, then endeavour to maintain this speed. I do NOT hang about, and yet still get quite passable fuel milage. Of course, slipstreaming a big truck all the way to work will return an mpg of around 60 mpg (which I have done in real life; I am not making this up) but it is boring and time-consuming.

  14. Dave Bell

    The Personal Factor

    Whatever the vehicle, the style of driving can make a bigger difference than these mods. And that's something we can all do.

    There's some things that seem a little counter-intuitive at first sight, such as final-drive ratios. But on some vehicles, such as a Land Rover, I'd wonder just what the ratio was optimised for. And any effect might be overwhelmed by the drag. But, on a pre-Defender type, replacing the 2.25 petrol by a later turbo-diesel made a pretty huge difference. Most of that is improved engine tech. On the other hand, that old 2.25 engine was very much a DIY engine. And there were a few problems that were fixable, if you watched for them, such as the carburettor gasket.

    1. Vic

      Re: The Personal Factor

      I'd wonder just what the ratio was optimised for

      Sales, of course...

      Vic.

  15. Anonymous Coward
    Anonymous Coward

    When you drive a classic

    Fuel economy goes out the window.

    meh.

  16. Steve Graham

    Heavy foot?

    The first car I had with a fuel-consumption display was a Saab 9000 Turbo. I discovered that, if I took enormous care and managed my acceleration and deceleration, I could get the MPG reading up to 32.5.

    However, if I just drove in my normal style, it dropped by a stupendous margin to 31.0.

    Yes, OK, probably it was my fault.

  17. N2

    Replace anything with "Lucas" written on it

    That made me smile.

    The other problem with trying to achieve good MPG in the UK is the roads, a poor road surface increases rolling resistance reducing MPG. Every car Ive owned over the last 30 years improves its MPG once were on our way home.

    For example our current car returns 33-35 MPG in UK which changes to 40-44 MPG in France, same car same fuel & more or less same temperature until were south of the Loire. Down vote me to hell, but the roads in the UK really do need fixing.

    1. Stacy

      Re: Replace anything with "Lucas" written on it

      No, you are being too kind to UK roads there.

      I live in Holland and drive back to the UK every now and then to see family. Driving through Holland, Belgium and France you can have a conversation in the car with ease. Then you get in the chunnel, get out and hit the M20 and any thought of a conversation goes out of the window as road noise increases by an unreal amount. The first time I did it I actually stopped to check there was nothing wrong with the car. If you drive something less sophiticated it can be even worse.

      When my Spitfire, with very uprated and hardend suspension, went back to the UK to await restoration (12 years and counting :( ) my dad was driving it with my mum. On the continent it drove brilliantly, he was amazed at how well it went. On the UK roads it continually pulled as the pits and tram lines in the roads pulled it left and right. Again he stopped to make sure something hadn't broken. It was only when he hit a small patch of fresh tarmac and suddenly everything was right again that he realised what it was.

      As for that wiring loom - aside from the concerns here about fire, I want! Spitfires have terrible wiring and anything that could make everything work as it is supposed to would be good! (And of course something to stop the switches on the dash melting when the power going through them gets too much! This was a wiring fault with the rear fogs!). Making everything low power with just a single bus delivering power to where it is needed sounds great.

      1. hammarbtyp

        Re: Replace anything with "Lucas" written on it

        I agree generally that the roads in Holland are excellent, but when I drove from Calais to Holland, it was noticeable how poor the roads got in Belgium and how good they got once you entered Holland...

        1. fandom

          Re: Replace anything with "Lucas" written on it

          In Belgium they light the highways at night, apparently that doesn't leave them much money for the actual road.

          The night lighting is awesome though.

        2. Stacy

          Re: Replace anything with "Lucas" written on it

          The motorway between Antwerp and Gent gets a bit bumpy in places, but we can still have conversations unlike the M20 when we get off of the train or the M6 between Stoke and Carlisle (i can't comment on the M1 or M25 as in the last 10 years I don't think I've seen them without major roadworks between Dartford and Leicester :p)

    2. Phil O'Sophical Silver badge

      Re: Replace anything with "Lucas" written on it

      our current car returns 33-35 MPG in UK which changes to 40-44 MPG in France

      Funny, my turbodiesel Mondeo gives me a consistent 36MPG in France, but usually over 40 in the UK. I generally put it down to the lower M-way speedlimits.

      As to road comparisons I fear that you are comparing expensive French toll autoroutes with British A-roads. Once your'e off the autoroute and motoring on ordinary routes nationales or departmentales you'll find that they're every bit as crap as UK roads in many places. It's like train comparisons, people compare TGVs to UK commuter trains and claim "French trains are better". Commute on a local TER and you'll have a very different view!

      Still, for really bad roads you should try a Californian freeway; potholed concrete-slab bumpity-bumpity-bump hell. I've seen country lanes with better surfaces.

      1. Stacy

        Re: Replace anything with "Lucas" written on it

        No, I'm comparing the motorways from Amsterdam, around Antwerp, round Gent and Brugge and across Normandy to Calais (all toll free). I know the motorways around Paris are shocking, but UK motorways are the next worst that I have driven on in my travels around Europe (Germany, Austria, Italy and Switzerland next the countries mentioned - I'll give you that Italy having toll motorways though)

      2. Conor Turton

        Re: Replace anything with "Lucas" written on it

        Funny, my turbodiesel Mondeo gives me a consistent 36MPG in France, but usually over 40 in the UK. I generally put it down to the lower M-way speedlimits

        Is it broken? My turbo diesel Mondeo returns around 55MPG both in the UK and France. City/rural roads it returns around 54-55MPG and on motorway runs as high as 65MPG, that's driving to the speed limits, not dawdling around.

        The only time I get down to 36MPG is when I'm towing my 26ft long twin axle caravan.

        If you're only getting mid 30's to 40MPG you need to look at the way you're driving it. Its not a petrol so you want to be changing gear much earlier and using the low down torque of the motor. Cruise in a gear that keeps you around 2000RPM and back off earlier approaching junctions and traffic lights.

        1. Phil O'Sophical Silver badge

          Re: Replace anything with "Lucas" written on it

          If you're only getting mid 30's to 40MPG you need to look at the way you're driving it.

          Oh, I know that :)

          It's a 2.2, lots of torque and great fun when you have a heavy right foot, and my consumption figures are pretty consistent with other owners. I could drive it like a nun and get better, I'm sure, but if I'd wanted to do that I'd have bought a Polo BlueMotion.

          1. Conor Turton

            Re: Replace anything with "Lucas" written on it

            I don't drive mine like a nun. In fact I spend most of the time going to work overtaking people and I'm just about at the point of needing to replace the tyres after just 25,000 miles.

      3. N2

        Re: Replace anything with "Lucas" written on it

        The auto-route is best & most roads are as good, a few through the villages are not so good as funding changes but work is on-going. Even our ancient Land Rover does reasonable MPG.

        We seldom see potholes where as in the UK its a continual challenge to avoid them & driving your side of the tunnel in Kent is like crossing a ploughed field.

        Driving at higher speeds on the auto route 130 Km/hr economy drops to 39.8 MPG, otherwise its low forties - UK government wont fix the roads because it gains more tax if they take more fuel.

        1. Solmyr ibn Wali Barad

          Re: potholes

          "UK government wont fix the roads because it gains more tax if they take more fuel."

          That's quite a stretch.

          Better explanation would be a chronic lack of funds. Weather conditions (freezing-melting-freezing cycles) don't exactly help either.

          1. Conor Turton

            Re: potholes

            They're spending a load of money on the roads. Here's a typical map of UK motorway and trunk road overnight road work closures. Its so bad I have to check every day before I go to work to see if I can actually do my job that night.

            http://i.imgur.com/nAa6Rxz.png

          2. Alan Brown Silver badge

            Re: potholes

            "Better explanation would be a chronic lack of funds. "

            There's plenty of funding, the problem is it's paying for management summer homes, not roads.

            Classic example was a new bypass road around 2004 (I forget where but it featured on the Beeb at the time) which was closed for major repairs before it even opened as the contractors had skimped on the roadbed vs specifications and it started coming apart in freeze-thaw cycles. It had to be ripped up and started over.

            Properly built road beds don't fall apart. Ask the Romans. Some of the best roads in the UK are laid over bases they put down nearly 2000 years ago.

          3. SEDT

            Re: potholes

            Better explanation would be a chronic lack of funds. Weather conditions (freezing-melting-freezing cycles) don't exactly help either.

            Yes the UK is the only country to suffer from freezing-melting-freezing, Hey ho, any excuse. Our government seem to have the funds for £20 billion blown in Afghanistan.

            1. Solmyr ibn Wali Barad

              Re: potholes

              "Yes the UK is the only country to suffer from freezing-melting-freezing, Hey ho, any excuse."

              I was merely hinting at a slight difference between continental climate and seaside conditions. As for mismanaged funding and lowest-bid construction tenders, that's hardly unique to the UK. Neither are potholes.

        2. SEDT

          Re: Replace anything with "Lucas" written on it

          Top dressing roads with grit ruins our environment, by not only increasing in-car noise, but more importantly, by increasing the volume of noise enjoyed by everyone living nearby

    3. Anonymous Coward
      Anonymous Coward

      Re: Replace anything with "Lucas" written on it

      I always put down my better MPG in France to the fact we in the UK get served crap petrol.

      When skiing, I will fill up in the UK and drive across France, fill up and climb the mountains, then fill up again a the bottom of the mountain and drive back, the return trip ALWAYS gets a better mpg.

    4. SundogUK Silver badge

      Re: Replace anything with "Lucas" written on it

      French roads, especially the toll motorways, just don't get the pounding that UK roads do.

  18. Anonymous Coward
    Anonymous Coward

    Also, old Jaguar bodies are cleverly designed to rust like buggery, and the corresponding weight loss does wonders for both fuel economy and passenger ventilation. Even better when the wheels fall off because your fuel economy then becomes infinite, at least until the petrol tank rusts through and deposits its load on your driveway.

    The joys of vintage Jaguar ownership. They don't make them like that any more.

  19. AlanBrand
    Coat

    Simple alternative

    The simple approach is to sell the Jaguar and buy a Morris Minor ... I just did that, 420 out van in.

  20. ngiger

    What about changing your life style? Buy a good bike and driving 100 miles per day is good for your health. Find a work place you may commute using your bike or public transportation, do not fly every year and your total annual consumption of energy will probably go done a lot more than tuning your nice car.

    1. MJI Silver badge

      I used to commute by bike, but the trip got boring so I went faster and faster until I got caught!

      large bikes cruised well around 70-80

      1. Anonymous Coward
        Anonymous Coward

        I think, by bike, he means bi-sickle, and not motor-sickle. As in people-powered.

        1. MJI Silver badge

          Stuff that - too much like hard work I have had cat A since 1980.

  21. Zog_but_not_the_first
    Thumb Up

    Cracking and inspirational article.

    I'm off to the car boot sale to see if I can get the rest of the car too.

  22. Anonymous Coward
    Anonymous Coward

    What about the fuel injection?

    Great article. This car is a prime candidate for junking the ancient ECU and replacing it with a modern hackable unit like a Megasquirt. You could have hours of fun with your laptop, tuning your car for optimum efficiency (or power, or whatever takes your fancy).

  23. Neil Barnes Silver badge

    As I have a horrendously long commute

    I amuse myself trying to reduce my consumption as much as reasonably practical... one thing I note is that modern turbo diesel is incredibly sensitive to both road surface and weather.

    Even a damp road will drop the economy by a mile a gallon; a belting down soaker will drop it five. Obviously the pumpling action of the tyres shifting water, and the rolling resistance of the car, change when it's wet. I note also that it's sensitive to wind speed outside the car, again, driving into even a mild headwind does nothing good for the economy!

    1. fruitoftheloon
      Joke

      Re: As I have a horrendously long commute

      Neil,

      headwinds - indeed, you could drive backwards[!]

      J

      1. Pedigree-Pete
        Happy

        Re: As I have a horrendously long commute

        The Austin AllAgro is more aerodynamic going backwards. Use one of those.

    2. MJI Silver badge

      Re: As I have a horrendously long commute

      headwinds

      I once managed 10mpg driving into a head wind while towing. So blustery I avoided the A30 across Bodmin.

      About 40l of propane after 90 miles.

    3. Nigel 11

      Re: As I have a horrendously long commute

      Even a damp road will drop the economy by a mile a gallon; a belting down soaker will drop it five

      Thanks - so that's what it is! I'd assumed it was because a busy wet road with lots of spray makes for "edgier" motoring, continuously having to adjust one's speed to the conditions and the traffic ahead (which will be displaying brake-lights far more often than the same traffic in the dry). Hadn't thought about the work involved in creating the spray.

      I'm now also wondering whether spray getting sucked in to your air filter clogs it, resulting in the engine becoming less efficient?

  24. Conor Turton

    Many of the things in the article have been implemented.

    Most things in this article have already made their way into production cars. Most cars now have smooth under trays covering the underside of the engine bay, electric power steering has been the norm for a few years. Ford used the flap design for the front grille in the Focus. My Ford Mondeo with all its electrical gadgets and a big heavy diesel engine weighs only a couple of hundred kilos more than my Ford Capri does despite being almost twice the size. LED lighting is now the norm in this year's production models and CANBUS has enabled load point switching.

    This to me is an article which is about fitting modern current technologies in use in production cars, applying it to a classic car and seeing the improvement. You won't see such an improvement in a current generation car because they're already using most of the suggestions in this article.

    One suggestion which hasn't been made is the use of a variable supercharger and turbo charger combination. Its what allows Ford's 1 litre econetic petrol engine to propel a car as large as a Mondeo, return over 50MPG whilst still having decent acceleration.

    1. werdsmith Silver badge

      Re: Many of the things in the article have been implemented.

      BMW call it efficient dynamics. All the same stuff, plus stop/start.

  25. harmjschoonhoven
    Boffin

    An other way to make cars more fuel efficient

    My late father improved the efficiency of the family cars, notably several Panhard PL 17's, by adding a retour pipe for cooled exhaust gases to the low pressure air-fuel mixture, controlled by a hand-operated valve. The pressure being measured with a vacuum gauge.

    Increasing the pressure (and temperature) in the cylinders gave a more complete combustion for a wide range of loads.

    BTW Panhard's forced air cooled boxer engines are not unlike aircraft engines with one instead of two sparking plugs per cylinder.

  26. david 12 Silver badge

    Killer...

    And I don't mean that in a nice way. The article starts by telling us that he's running lean, producing NOx, which has a long known and easily measureable effect of increasing deaths due to respiratory failure in communities around roads, which is pretty much everwhere, and worst where there are the most roads, which is where there are the most people.

    The solution is run rich. Which increases hydrocarbon emmissions. Which are cleaned by catalytic converter. Yes, that makes you less fuel efficient. Yes, they know that, but they did it anyway, because they decided it was a fair trade-off for killing fewer people.

    The technology to run lean on production cars only really became available at about the same time as people realised that it should be made against the law to run lean on production cars. So no surprise that now, many years later, he can tune this car to run lean. And yes, he can piss on everyone else because they failed to make it illegal to do that to an old car. But he's an a-- if he uses that as an excuse.

  27. keith_w

    I have a 38 month old ford fusion 2.5l with 95,700kmand get 8l/100km (35.31mi/imp gal)

    1. Jan 0

      @keith_w

      and?

  28. Sorry that handle is already taken. Silver badge
    Windows

    Interesting cars

    The article says that cars are a good way to meet people. I've spent time around car clubs and the only thing anyone has in common is their ownership of a particular car. My experience otherwise hasn't been amazing, but they were "modified car" clubs so that's probably the reason.

    I drive an unmodified, current model mid-range Japanese sports car that I didn't think was amazingly interesting and people come up and tell me they like it in car parks, but neither ask nor say anything further. I wish they'd stop.

  29. Christopher Aussant

    Thats it?

    I admit to not knowing about hypermilling until now, and clicking the link in the article didn't load the page(my internet is a bit screwed right now), but I can't help but be dumbstruck by the shallowness of the article....

    There are FAR more things that can be done to a vehicle that the author hasn't mentioned, done, or perhaps thought of. I'll list some off here in no particular order of importance:

    1) Supercharging or turbocharging the engine. While this is an expensive and sometimes time consuming endeavor(I personally installed a supercharger on my 2010 dodge challenger srt8), the benefits are amazing. An engine is simply put an air pump. Doesn't matter if it runs on gasoline or diesel, the majority of what passes through the engine is air. In the case of the article, the motor he uses is gasoline powered. Gasoline burns in a concentration of 4-9%, So depending on the tuning and setup, the engine is pumping 91-96% air through it. Increasing the efficiency of the air movement adds performance and fuel economy. If the engine has more power, it doesn't need to work as hard or as long to accelerate or maintain speed. On the cheap one can look into a ram air setup. While not helping at low speeds, at cruising speed its a poor mans turbo and helps increase your efficiency. Although if you wish to simply slap on the fake hook scoop stickers, please step out in front of a moving bus before you do....

    2) Changing engine components and polishing them. The air going to the motor should take as few turns as possible to reduce losses. Every bend in an air intake system reduces power. The air filter is a necessary evil, but there are higher performance ones out there available at decent prices. Not ALL filters add amazing power savings and mileage and do your homework. Next up, the intake manifold and the cylinder heads. Aluminum intake manifolds are available on the aftermarket for a large amount of vehicles. Polishing the intake and cylinder heads reduces friction of the air flowing inside them, increasing efficiency. Its not all about the amount of air being forced into the cylinder, the velocity of the air has a big impact as well. Valves in the head can be helped with a three angle valve job.

    3) Exhaust. Scavenging is the term given to using the flow of exhaust creating a vacuum to draw the unspent gasses out of the cylinder. Its a common myth that you need backpressure for the vehicle to work properly. While the vehicle does require some for scavenging to work properly, too much restriction causes the engine to have to work harder to push the gasses out and drops efficiency. Equal length headers to a proper sized exhaust system with an h-pipe, or x-pipe depending on your vehicles needs can not only help it sound better(for some of us who enjoy the roar), and help with the mileage as well.

    4) Weight distribution. Relocating the battery to the passenger side of the trunk to offset the weight of the driver in the front left is common in north America now, but across the pond I guess you'd put it on the other side. While carpooling is great, a lot of us have to drive alone so balancing the weight load in the car helps. Removing items in the car that you don't need to carry with you improves mileage as well.

    5) Wax. Yeah, just waxing your car helps. Unless your car is brand new and has a perfect clear coat on top of the paint, you're going to have micro pits in the paint, and while they are small, they are numerous. Given the sheer amount of air rushing over the surface of the vehicle, putting a $7 bottle of wax and some elbow grease to make it nice and smooth helps reduce the drag on the vehicles surface. Also helps protect it from the road salt and washing it is a lot easier.

    6) The temperature of the fuel. Yeah, lets get radicle here. If you're wanting to modify this for some fuel mileage, lets have some fun. The density of your gasoline changes with temperature. When its colder out, your gasoline is denser. Your fuel pump doesn't care about this density change, it just pumps its set amount of liters per hour and throws them down the pipe. Adjusting this can be done passively. Take a line off the engine cooling lines using a high thermal conductive material and run it along the fuel line to pre-heat your fuel to a set temperature (the engines operating temperature). Or you could design an in tank electric system to run off a thermostat and set the desired temperature yourself with testing to find the best temp. Getting more dense cool air into the engine and a set temperature and density of fuel with it can help achieve more mileage. This will need to be done with SOME consideration of risks. You don't want electrical fires in your gas tank. Heating and thereby expanding the fuel too much can reduce how much fuel you actually get and reduce power. A system where you can turn on and off the fuel line heat to run colder denser fuel for more power for say a hill or passing cars then hitting a switch and heating it for fuel mileage is another thing to try. Again, you have to consider the engine requirements to get the most out of this.

    7) Using the research of race teams. Almost all of the improvements we enjoy in our modern vehicles are the results of the racing industry pushing boundaries to get all the edge they can. Exhaust headers, blowers, air foils, lightening the vehicle with fiberglass and carbon fiber components, etc. Someone else has already done this research, use it to your advantage.

    Theres SO MUCH MORE that can be done, you've barely scratched the surface with this article.... AND this list was all off the top of my HEAD! I'm no automotive engineer, just a guy with a few tools and time on his hands....

    1. David_H

      Re: Thats it?

      Just to back up one of the previous recommendations:

      When the cost of diesel started to reach dizzy heights in the UK, I worked out that it was worth £5 on the wax car wash every time I filled the tank. (However, of course, not filling the tank, but putting just enough in for a few days travelling, would have saved even more on the economy!)

      2.5l Diesel 2006 Honda CRV: 53mpg on a motorway run on my own, and 24mpg when towing the 26' caravan with the family! Those and the round town figure of 39mph suggests that Honda slightly under power their vehicles for fuel economy. And they do use CAN bus and a lot of the other tricks. I make sure the tyres are fully inflated, the brakes are not binding and I put the PTFE additive in the engine after each oil change (not until it had done 100,000 miles though otherwise it could seize up).

  30. Hans 1
    WTF?

    Drivers urged to speed up to save on costly diesel particular filter DPF repairs

    LOL, I know a guy in a BMW dealership ... all they do is replace the DPF, get the Kaercher to clean the used part (as long as customer does not request to have it back), and sell it second hand.

    If your DPF is blocked, get yourself a kaecher and clean the f'ing thing.

  31. Anonymous Coward
    Happy

    I've gone one extreme to the other....

    I've built and owned a kit car, and now own a little (new) Hyundai i10.

    The Tiger (kit car) was tuned to go fast, end of. Twin 45's, fast road cams, race tuned engine, the lot.

    "Good" careful driving, 20 - 30 mph. err "Proper" driving, err maybe 5 -10, if I'm not trying to kick out 2ft flames out the exhaust, then you are looking at 3 or 4mpg (look fantastic at night though).

    I could of retuned it, but whats the point, that's not why I bought the car.

    .

    Now the i10.

    That has changed my driving a lot by using "nag" mode. The mpg is set to update constantly, I now try to get it hitting the magic 99.9pmg as much as possible. By doing this, my average has gone from 45mpg to 52mpg, but on the motorway, on the falt, using cruise control, that can easily hit 70mpg.

    .

    One thing this car has shown is how even "minor" thing really affect the performance.

    Switch from one road surface to another and you can see it drop by up to 5mph (easy on the motorways round by me). Even a slight incline will drop it by some amount, a slight decline of course does the reverse, a steep hill really affects it, so much so a bigger engined car may well be more efficient.

    Tyre pressures of course do, running a slightly lower pressure, knocked about 5mpg off.

    .

    The two cars do have one thing common, weight. neither weighed anywhere as much as my previous cars, but adding extra people or goods really, really affects the performance. In the kit car, some of my friends would add almost 15% extra weight to the car, despite only being a two seat. Add the wife and kids to the i10, your looking at 20 - 25% extra.

    This makes one of the biggest diference for all of them

  32. Ken 16 Bronze badge

    Check out the bumper bars

    Excellent article.

    I believe (from racing development) that the steel front bumper bar can be replaced with the aluminium equivalent from the XJ40 for substantial front end weight saving (and steering lightening) while there's an outboard disc swap which doesn't save anything except time in replacing pads.

    I'd love to read more about the logic controllers you used on the air con and alternator.

  33. James Pickett

    "a heat exchanger that heats the engine oil"

    Seems a bit unnecessary - the engine will warm up the oil directly, as the author later admits. Also, if the thermostat is working properly, water will not be circulating when cold and the pump will have relatively little to do. Centrifugal pumps are loaded by flow, so not inefficient.

    1. MJI Silver badge

      Oil heat exchangers

      Actually they are pretty good, they heat the oil up quicker to operating temperatures and then keep them from getting too hot.

      Warms the engine up quicker

      1. Sorry that handle is already taken. Silver badge

        Re: Oil heat exchangers

        My modern car with its fancy tech gets its engine coolant up to operating temperature within about a kilometre, and no more than two in the dead of winter. The oil takes 5-10km to achieve the same. You'd expect getting every part and fluid up to optimum or operating temperature as soon as possible (within reason) to be beneficial for both efficiency and longevity.

        Some high performance cars even come with recommendations not to drive them too hard until the oil is up to temperature, and rightly so.

  34. tiggertaebo

    Interesting article but...

    ..the IMHO unnecessary preachiness from El Reg at the end left a bit of a nasty taste in the mouth.

  35. Unicornpiss
    Flame

    Hypermiling

    Perhaps because I live in the US where gas is still relatively cheap (you may all begin calling me a cunt now), but I HATE being behind someone who is hypermiling on a 2-lane road. And especially hate Prius drivers who are watching their efficiency monitor instead of the road. Thanks so much for making my day a little more aggravating and presuming to be the leader of all traffic behind you, just so you can save an extra $1-$3 per fill up. I am one of those drivers that enjoy driving a decent car in a spirited manner, and it is anathema to me when someone in front of me decides that getting from 0-60 in 2 minutes is perfectly acceptable. All too often these oblivious drivers ignore the speed limits anyway. They will blithely take all day to reach the posted speed limit, only to keep accelerating on past this point, albeit as slowly as though their vehicle has a solar sail and not an internal combustion engine.

    Before the flames begin, understand that I have no problem with hypermiling if you are not impeding traffic and will practice it myself when it makes sense, such as when there's little traffic and I know the light ahead will be red by the time I reach it. People that race ahead of you to have to slam on their brakes at the next red signal are a whole other annoyance. Perhaps I just hate everyone...

    1. Anonymous Coward
      Anonymous Coward

      Re: Hypermiling

      "Perhaps I just hate everyone.."

      Nothing wrong with that.

      1. Darryl

        Re: Hypermiling

        "Perhaps I just hate everyone.."

        "Nothing wrong with that."

        Exactly. It's also the only sure way to avoid being a racist.

    2. Trygve Henriksen

      Re: Hypermiling

      Can't blame you...

      I once overtook a 911(9something anyway) with my 1999 berlingo(replaced the 1998 mentioned in another post after a cunt with a SUV but no clue wreced it in a parking lot)...

      Boy does the 1.4i scream when you throw it from 5th(it was doing 60Km/h) down to 2 and flooring it.

      Woke up the b@stard in the Penisextender, at least, since he overtook me on the next straight part of road(read: 5Km later. This is Norway after all)

      It was worth it to take that hit on the mpg...

      Yeah, I'm a bit of a bastard...

  36. Anonymous Coward
    Anonymous Coward

    Turn off the engine while downhill!

    I heard about some hypermilers that not only replace all those parts by electrical parts, but also make them available even with the engine turned off. COMPLETELY off.

    I'm not really sure, but even the brakes and some form of electrical generation also running straight from the wheels helps keeping stuff working. Of course, the steering lock is disabled or otherwise modified so the car won't lock while coasting.

    And I've seen that the Nissan Leaf has solar panels to power the air-conditioner. Nothing prevents you to do the same... except for the weight, perhaps?

    1. JeffyPoooh
      Pint

      Re: Turn off the engine while downhill!

      "...the Nissan Leaf has solar panels to power the air-conditioner..."

      You're not very good with numbers, are you? A small solar panel might be capable of powering a fan to move hot air out of the cabin, keeping it at ambient. But a solar powered air conditioner would need (much) more than a square foot of capture area of solar panel in the 10 watt class.

      Ref. "The Leaf's SL trim has a small solar panel at the rear of the roof/spoiler that can trickle charge the auxiliary battery."

    2. Phil O'Sophical Silver badge

      Re: Turn off the engine while downhill!

      Manually turning off the engine in a moving car has to be one of the stupidest suggestions in this whole thread.

      Firstly because it's pointless, if you're travelling downhill in gear, on a closed throttle, in a modern car there will be no fuel injected anyway, the ECU will see to that.

      Secondly, when you're in charge of a ton and a half of steel travelling at several tens of MPH you need to be ready for any unexpected situation, and that means being able to accelerate or steer rapidly as well as brake suddenly. You don't want to be fumbling for clutch pedal and ignition key and trying to restart in an emergency.

      1. adam 40 Silver badge

        Re: Turn off the engine while downhill!

        oh that's easy - keep the car in gear with your foot on the clutch, then turn off the ignition and turn it back on when the engine has stopped. Restarting the engine is simple, you let your foot off the clutch and floor it if you need to.

        If the brake vacuum reservoir empties you can let your foot off the clutch too.... but that normally lasts 4 or 5 presses.

    3. Pedigree-Pete
      Thumb Up

      Re: Turn off the engine while downhill!

      Yeh! I tried that with my Dads 2.8 Granada (The Sweeny one not the later travesty). Soon found out I couldn't steer :(

  37. Apdsmith

    Does anybody else, reading this, get shades of the bionic man intro...?

    1. fruitoftheloon
  38. Anonymous Coward
    Anonymous Coward

    Low energy tyres and fully synthetic oil? The latter may not be suitable for an old jag but if the engine were rebuilt anyway (with blueprinting and gas flowing) and to modern tolerances then it ought to be ok.

    With tyre pressures set on the high side of the range that should give another 5-10% on any car.

    1. Nigel 11

      With tyre pressures set on the high side of the range that should give another 5-10% on any car.

      NO NO NO.

      It's at the cost of decreasing your tyres' life (because the tread in the middle will wear faster than the edges)

      And at the cost of increasing your stopping distance, which might kill you or someone else. Or less dramatically, just raise your insurance premium considerably after a very minor bump that's your fault.

      And since it's illegal to have over-inflated tyres, this might end up with you in jail or being banned from driving.

      1. Anonymous Coward
        Anonymous Coward

        Tyre Pressures

        I have found that the car makers tyre pressure suggestions are all on the low side; given that a car often has two or more suggested pressures (load speed-low load and high speed high load), I tend to pressure my tyres somewhere in between for normal use.

        This gives a better response when turning at urban speeds, less roll, and stops the tyre wearing on the outside edge so much.

        My current tyres are set at 2.2bar (min/max is 2.1/2.3), and the MOT report says there is less than 1mm difference in tread depth between the middle and the sides as they approach half worn).

        In my old Toyota MPV the difference was HUGE, with 2.5 min and 3.0 max; setting the tyres at 2.5 meant it wallowed around corners, and downright dangerous in the wet while 2.8 made it handle much more like a saloon car.

      2. LucreLout

        It's at the cost of decreasing your tyres' life (because the tread in the middle will wear faster than the edges)

        It might be if I didn't have to continually replace all 4 due to potholes blowing them part way through their life * I never over inflate my tyres, but I do run them at the "fully loaded" setting, even if it's just me in the car. Thanks to the golden rule, I've not hit anything in many many years.

        * AWD so you can't just replace the one tyre unless you have it shaved down to the same size as the others. Transmission windup is not cheap to repair. So every blow-out is four new tyres.

        1. Anonymous Coward
          Anonymous Coward

          have to continually replace all 4 due to potholes blowing them part way through their life

          In an earlier post you complained that ABS prevented you slowing down before a turn in snowy weather, now you complain about damaging your tyres when you hit potholes.

          Ever thought about looking further ahead, and anticipating hazards early, instead of just trying to react when you reach them?

      3. Fungus Bob

        "It's at the cost of decreasing your tyres' life (because the tread in the middle will wear faster than the edges)"

        That's the old conventional wisdom from the days when bias ply tires roamed the earth and color television had not yet been invented. Modern steel belted radials will not exhibit the tread wear you describe unless inflated to around 100PSI, well above anything useful for driving and not killing one's kidneys. Max pressure also reduces hydroplaning and tire wear. ( http://www.cleanmpg.com/forums/archive/index.php/t-11652.html ).

  39. nijam Silver badge

    Given my normal commute, two external parameters have a significant effect on fuel consumption: ambient temperature (lower temperature -> worse fuel economy) and other traffic (more traffic -> worse fuel economy). Regrettably, I still can't control the weather, but I do have enough freedom to avoid travelling at the worst of rush hour.

  40. 404

    Even newer vehicles can benefit

    On my 2008 GMC Canyon extended cab pickup with a 2.9l 4 cylinder/auto transmission - EPA sticker claimed 23-29 MPG, real life was barely 20 MPG (governed to 99MPH) when it was new and totally stock. This is where vehicle fan pages come in, they help with the individual idiosyncrasies of whatever vehicle you might have. Problems, performance, and general upkeep procedures can be found there. With that said, what I did with my truck to increase mpg/performance (in my mind, performance/efficiency equals MPG - better performance, less foot needed, better mileage).

    K&N cold air intake

    gutted 1st catalytic converter

    ported & polished intake/exhaust manifolds

    ported/modified throttle body

    Flowmaster exhaust w/sierra flexible SS braided expansion joints

    NGK iridium sparkplugs

    Beryllium copper spark plug->coil pack connectors

    Corvette shift servos

    All synthetic oils for less friction

    Belltech antisway bars

    Hypertuned for 89 octane, better shift points, delete traction control, de-GM'ed extra clutter from ECM/BCM

    Low rolling resistance Michelins

    Now, even with 155000 miles on her, she gets 28.8 MPG average & tops out around 137MPH.

    Really only concern I had with the Jag rebuild was the final gear ratio - seems to me it would be a dog to get rolling, but once there would just cruise at max mpg - seems it might cancel out each other as far as benefits of the waaaay-beyond-highway gearing.

    1. Trygve Henriksen

      Re: Even newer vehicles can benefit

      89 Octane?

      No wonder fuel is cheaper over there... you get the dregs...

      Here in Norway, 95 octane is 'normal' and 98 is 'high octane'.

      They also sell 92 octane in and around Oslo. It's probably OK if all you do is sit trapped in rush-hour traffic.

      1. 404

        Re: Even newer vehicles can benefit

        Are you shitting me?

        We get 87, 89, and 91-2 octane at (currently $2.84, $3.04, and $3.24/ gal respectively. Diesel? $4/gal. I tuned for availability and median price...

        dreams... what I could do with 98 octane.... sigh. Off to twitter to bitch at White House... fuckers... all this time telling us 'it's the world price, not us'.. paying higher prices for shit gas..

        1. Lord Raa

          Re: Octane

          I'm not sure if the same method of octane rating is being used both sides of the pond. But yes, 95 octane is standard in the UK.

  41. James Pickett

    "the overengineering in the past meant that things were heavier"

    Really? The original Ford Cortina (including propshaft and rear diff) weighed just over 800kg, a current Focus weighs at least 1270kg!

    1. John 62

      Yes, but the Cortina didn't have all the extra gubbins the Focus has. Plus, the Focus is HUGE compared to a Cortina.

  42. captain veg Silver badge

    torque

    "Engine friction can be reduced simply by changing the gearing it to run slower to produce more torque at lower rpm."

    That is.... illogical, Captain.

    Upping the gearing will indeed allow you to exploit the reduced weight and improved aerodynamics, but it won't change the torque curve of the engine one jot.

    For urban driving, you can get much the same effect anyway just by changing up earlier.

    -A,

  43. Nigel Whitfield.

    Even simple maintenance helps

    It's perhaps stating the obvious, but given the number of people you can see driving around with failing lights, and sagging tyres, worth stressing that just keeping on top of basic maintenance like the tyre pressure helps.

    I drive a 1973 Citroën DS 23 EFI; it's just had a replacement radiator fitted, and while it was in, the points were adjusted. Before the most recent trip, I also noticed the rear tyres were about 6psi down.

    That has made a pretty huge difference; on two comparable trips (long motorway drive, plus pottering round at the destination) I've gone from 20.4mpg to 26.5.

    An awful lot of people would very likely get much better performance from their cars simply by doing some basic checks before their journey.

    1. Anonymous Coward
      Anonymous Coward

      Citroën DS

      Aaaah - one of the world's most beautiful car, truely a godess :-)

      IIRC, when we used to drive Diannes, if the milage dropped below 40 it was time to do a service. But we used to thrash the balls off them anyway, so who knows what they might have done had we cared.

      I can get the current 2.5L C5 down to 12.7mpg and up to 80+ in the short slip road from my drive to the main road - hipermilers are such sad muppets :-)

    2. I Like Heckling

      Re: Even simple maintenance helps

      True... just keeping on top of maintenance, with oil changes every year regardless of mileage (I average less than 5k a year), keeping the fluids and pressures at optimum, or as is the case with tyres, a fraction above optimum... So as mine is supposed to be 32 psi, I keep them at 34 psi.

      Manufacturer specs my Mondeo diesel at 58mpg, yet on long motorway trips using the cruise control... I've averaged 64 mpg at times.

  44. James Pickett

    I find it hard to believe that replacing a copper wiring loom with an aluminium one will save enough weight to make a measurable difference to fuel economy. It's filthy stuff to make a good connection to, too - we have aluminium phone lines round here, thanks to a copper shortage in the 70's, and BT are forever re-making the connections in the local junction boxes, due to corrosion.

    A much simpler way to improve economy is to add a small measure (0.2%) of acetone to the fuel. This reduces surface tension and improves atomisation, with a resultant smoother burn. I've used this in two cars and one motorbike, with an overall 8% improvement in economy. The bike, in particular (as it's a twin) runs more smoothly and is more tractable at low revs. I've been doing it for some years, with no ill effects or damaged seals. It works with petrol and diesel, but increasing the amount does not help - I use 20ml per 10litres.

  45. Paul

    You can buy a basic bluetooth to OBD2 adaptor off ebay quite cheaply, it's quite interesting to use a smartphone app (e.g. Torque on Android) and see the engine management's workings... air intake flow and temperature, turbo boost, engine load etc.

    A few years ago now cars were switching over to using CAN bus for control, makes the wiring loom simpler with a power bus and separate control bus, but also allows good diagnostics helping notify blown bulbs etc.

    My recently purchased Qashqai has electric power steering rather than using hydraulics. I am not sure if the air con is driven by the engine or has an electric pump, I would guess the ones with the larger diesels are driven by the engine, but the new 1.2 turbo petrol might be electric.

  46. Anonymous Coward
    Anonymous Coward

    Not all cruise controls are created equal, my Mercedes E class would apply the brakes when descending to keep maintain speed at the programmed value, unlike my rental Astra that just accelerates beyond the programmed speed when descending... The E 220 diesel averaged over 41mpg, this is a seven speed auto, one and three quarter tonne estate, which I reckon was pretty good. The 1.4 turbo Astra is too lively from a standing start and won't pull the skin off a rice pudding going uphill unless the engine speed is over 3,500 rpm, which implies an illegal speed or going up in 4th - its no more economical than the Merc.

    Running a mechanically simple, repairable at the roadside car is ecologically far more sound [IMHO] than a new 'zero emissions' electric car - stand up the first person to do the 'whole life' CO2 emissions equation - manufacture, use and disposal, 'cos I don't think a wind turbine generates electricity with zero emissions - that's just a lie.

  47. Gary Bickford

    Carbon Fiber (once the $$$ reduce to $), and electric braking

    Reading about the use of the AUDI door element, I immediately thought of using carbon fiber for that - it would reduce the weight to a few ounces (it's amazing how light a CF element can be, especially using an isotruss-type structure). This could be used other places as well. But - sigh - first the price needs to go from $20/kg to $2/kg.

    Reading the comments, I thought about using adding a simple battery + motor-generator system to one or the other axles, which could use energy generated in braking to add to the next acceleration. If the purpose is limited to this short-term application, the system might be small enough to fit into the plan. There are some motor-generators that are very wide and flat (similar in shape to a disk brake), and are very light, though they cost $2000 apiece 10 years ago, last time I looked.

  48. I Like Heckling

    Interesting article, but ultimately pointless in some regards... I do agree that keeping an older car on the road is more cost effective than trading it in for a newer and more economical one. though, I've done that myself to a certain degree.

    I used to own a nice V6 coupe, 200bhp (import version) and according to manufacturers specs, capable of 32mpg extra urban. Now bear in mind that when I got my hands on it, it was already 14yrs old and had been neglected a fair bit.

    I replaced the knackered clutch with an uprated one, and fitted a lightened flywheel shaving 9lbs of it's 23lb weight. I fitted larger and yet lighter wheels, I improved suspension and braking, added extra torsion stiffness front and rear and fitted a fully stainless system with custom manifolds. I also improved airflow into the engine and fitted a larger catalytic convertor (jap ones were a third smaller than EU ones). I then set about making sure the engine was in tip top condition. Luckily these engines are pretty bullet proof and after some new gaskets,a proper flush, new O2 sensors, plugs and leads... I took it to the Nurburgring. On the 450 mile trip from the UK to Germany and with a car full of camping gear and 2 people, we averaged just over 35 mpg. We travelled at an average of 60mph, with occasional blasts up to 80 mph for overtaking, or just a little fun. If we'd stuck with a steady 60 the entire way, that could easily have been 36-38 mpg. In an unloaded car with only the driver, on a 250 mile motorway journey, she averaged 37 mpg. When put on a rolling road she topped out at 223 bhp.

    I imagine that had I removed the aircon pump, and gone to electric steering and a more efficient alternator... I took could have seen 40+ mpg.

    But the problem is... it's no fun owning a sports car and then driving it like a doddery old fool out for a Sunday drive at the slowest speed you can get away with. These cars were meant to be driven, and 90% of my driving was short journeys of around 25 miles at a time... and I averaged around 24-25 mpg... Because blasting around country roads on the way to see people is a lot more fun than driving in a car convoy of friends on the way to a racing track and trying to save as much money on the trip out, because you knew you'd be wasting all that fuel on the track.

    As for the track time itself... in 7 laps of the Nordschleife I averaged about 17mpg and completed the circuit with a best time of 9 mins 48s... It wasn't the car, but the driver that ran out of nerves and was a little more conservative than I could have been... But that said, Lap one took 11 mins 23s and I improved on each one after that shaving 1 min 35s of my time. With more practice time, more money and better tires... Who knows how much more I could have shaved off.

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