[HighlandPete]

Originally Posted by The Beast

Surprisingly this study was done some time ago with the results being presented two years ago. Apparently VW were present at the presentation.

It has only just blown up in the media now after government testing...

There's been a build up of data over the past few years on the failure of the NEDC test to represent real-world figures, but the issue is such a hot potato and gets pushed into the background, even when there has been exposure.

What seems to be the difference here, whereas the reports and studies focused on MPG and CO2 levels, this latest set of tests (NEDC and EPA regimes) show an anomaly with NOx emissions. Large discrepancies in real-world emission levels, compared to the official tests. Puzzled at the results, more investigations and this latest exposure.

Manufacturers have not been in favour of rapid implementation of the new Worldwide Harmonized Light Vehicles Test Procedure (WLTC) under development, originally due in 2016. It is reported many involved want it postponed to at least 2020.

We may wonder why, but with what is as accepted as manipulation (gaming as it has been called this week) of the existing test regime, no surprises on delay tactics when the new test will have a real-world test element to it.

I think we can be sure that this past weeks exposure will change attitudes.

HighlandPete

[alexank]

What I find odd and this I think might suggest we will eventually learn that they have "all been at it" is surely manufacturers look at their competitors products in detail and should have noticed.

If a given car is better from a performance MPG and emission point of view then you would expect a competing manufacturer to go over it in detail to find out where it has the edge. During that analysis surely they would notice things don't stack up so then why not get the upper hand and blow the whistle?

Perhaps instead they have been doing exactly the same or simply copied the idea?

[IanS100]

Unless of course, their nefarious tactics had simply put the cars where you'd expect them to be 'from a performance MPG and emission point of view'?

[shiner]

I think we've all known for a long time that the figures claimed by the manufacturers and the reality encountered by the rest of us are poles apart. And that's for stuff that we as drivers can easily measure on a daily basis - i.e. fuel consumption. BMW's (and to be fair other makers too) fuel consumption figures are a fantasy.

So it begs the question; what on earth are they up to on stuff that we as drivers CANNOT measure!

[DDarkEnergy]

Originally Posted by shiner

I think we've all known for a long time that the figures claimed by the manufacturers and the reality encountered by the rest of us are poles apart. And that's for stuff that we as drivers can easily measure on a daily basis - i.e. fuel consumption. BMW's (and to be fair other makers too) fuel consumption figures are a fantasy.

So it begs the question; what on earth are they up to on stuff that we as drivers CANNOT measure!

Is not the manufacturers fault if the test is not realistic.

I can easily reproduce the "oficial" figures with my car driving in the MW at not more than the average speed of the Extra-Urban Driving Cycle and keeping accelerations and braking to a minimum. The problem is that the average speed of the EUDC is ridiculously low for modern cars: 39 m/h !!.
Now who drives like that to day?

[IanS100]

The problem isn't that the figures were unrealistic, it's that the car had a super clean test mode that was only used when certain parameters were met ie the car detected it was being tested. As the car never used this super clean mode while being driven, it was totally impossible that the figures could ever be matched while driving, no matter how carefully the driver was with speed, braking and acceleration.

[HighlandPete]

Originally Posted by DDarkEnergy

Is not the manufacturers fault if the test is not realistic.

I can easily reproduce the "oficial" figures with my car driving in the MW at not more than the average speed of the Extra-Urban Driving Cycle and keeping accelerations and braking to a minimum. The problem is that the average speed of the EUDC is ridiculously low for modern cars: 39 m/h !!.
Now who drives like that to day?

We definitely need a realistic test regime.

We hear the argument that it is only a comparative test, which it clearly is, but that doesn't work in practice, when we don't drive as light as the test.

If the test was formulated to be simulating the average of how we drive today, then the comparison idea may be more reflective in the real world.

The light loads of the test when compared, don't follow the same pattern when the loads are higher. The comparisons can then be so different. For example, NEDC combined figures may show a shortfall of 10% for one car in realistic driving, another 35% in the same driving. The tests must close that gap or there is no real credibility.

HighlandPete