Re: What will be interesting is the corrective action...
@Arnuat the less
I do not see the relevance of that paper to whatever point you are trying to make.
Para 1, sentance 2:
Any change in the fuel injection pattern during the ignition delay period affects the quality and the timing of the combustion process, as well as the vibration levels of the engine structure.
I agree that the S3 does suggest it mostly afflicts idle:
Especially at low engine idle speeds (600–800 r/min), fuel economy and reduced emission requirements lead to increased combustion irregularity
However, it is not exclusively at idle that this is felt, and with a frequency ranging from 1hz to 400hz, its going to be very noticable to the driver. As most time spent in most cars is around town or stop start traffic, your idle shake is a key concern.
It says nothing at all about length of injection period, because at idle that is going to be short anyway. Your "long high pressure injection" is totally irrelevant.
Only if you understand nothing about engines; I'd assumed perhaps incorrectly that you did. Otherwise you'd already know that increasing the duration and pressure of fuel injection will increase the emission of CO2 while reducing the emission of NOx and particulates. Typically this is done with several injections of fuel per ignition stroke - the pilot injections for smooth running, the primary injection which makes the power, and secondary injection(s) for clean burning. If you care not for the lumpiness of the engine, you can likely skip some or all of the pilot injections, there by reducing CO2 - you then fuel up the secondary injection to burn off the NOx. What you gain is a hell of a lot of vibration.
In short, to meet (most of) the environmental criteria they claimed to have met, their cars will feel more agricultural and generate a bit less power; or the alternative is that they generate a lot less power but still feel relatively vibration free. Which is what I said earlier.
Carbon particulate filters are a major cause of customer dissatisfaction, which is why you don't want more carbon particles produced.
I agree, which is why so many have been removed after failure. They will get you through the EURO 6 test though.
Anyway, the net conclusion is, don't buy VW shares. Honda or Toyota could be the major beneficiaries of this one.
Agreed, in part. Though once the testers wake up to the concept of multiple mappings having also been applied to petrol cars to game CO2 and MPG figures, I expect the scrutiny to reach other marques.