Re: Where's the red line?
"The other problem here is that too much credence is applied to the test results."
Indeed. In fact it will be very difficult to have a test that accurately reflects 'real-world' usage as that varies so much.
The extremes might be the city dweller who mostly does short trips in busy conditions with lots of stop/start/idling/acc.
My car might be the other extreme - almost no short journeys, live in the country, travel mostly fast A-roads and motorways at quiet times (overnight), little acc.
I suggest no testing regime will adequately reflect that and that's without considering driving 'style'