I posted this in the Pit thread about VW, but for some reason it never gained traction.
VW is not alone. It turns out that many, perhaps all, of the European auto companies do something similar, although the way they do it may be different.
To a large degree, the problem is systemic.
The Detroit Free Press has a pretty good article on this issue.
Emissions limits are set by the EU, but enforcement is up to each nation, and you only need to pass one country’s test and you’re good for the whole EU. This leads to a lot of “forum shopping” for the easiest place to pass.
The rules also seem to tolerate a fair amount of gaming the system:
All of this leads to test results are, ahem, “optimistic” compaired to real-world results.
Frustrating to be sure, but it’s still a step or two removed from the blatant fraud that VW was committing.
As long as the standards are set in such a way that they take into consideration the fact that the automakers can do these things to manipulate the results, there isn’t an issue, and indeed the real world values will differ significantly from the tested values. If all you’re doing is comparing tested values and everyone “cheats” in the same way which isn’t really a change from how it operates in the real world, then it’s a fair method of gaming the system as it’s totally intended to be gamed in that way, knowing that the manufacturers will be able to do such things and planning for them in the standards. Telling your car’s engine to change how it runs when detecting test-like conditions is something else entirely.
I don’t know a single person who expects to get the MPG as tested.
Literally no-one. We all know that the tested figures give us a relative rather than an absolute performance. It has to be that way because of the huge amount of variables in real world driving (the biggest variable is the person behind the wheel.)
eg. The consumption figures for my car (a skoda Octavia 2.0 diesel - VW engine) is 58.9 urban, 78.5 extra urban, 70.9 combined.
On a typical 20 mile journey of mixed urban and country road I get 62-65 mpg, my wife gets 10mpg less. Weather also makes a difference, wind with or against, raining, cold or hot, fully loaded or single passenger etc, etc
So personally I’m perfectly happy to have a known, unrealistic figure that allows us to rate cars relative to each other.
As for this being just a European issue, I very much doubt it. US and far east manufactures are just as likely to trying to cheat the system.
The difference is fuel economy is controlled largely by your right foot. The function of the emissions control system is not (unless it’s a VW.)
The problem with VW (and we’ve had enough threads here in different forums where I wish people would read a little more into things before spouting off) is that VW deliberately set out to cheat on both the EPA and Euro NCAP tests.
for as much as people in the US complain about their cars not meeting the ratings on the sticker, the EPA test procedure is still way tougher than the EU test. the NEDC test is a sad, sad joke.
Sure, it is just what you get used to though. Implementing a more stringent EPA-style cycle will likely produce a more accurate “real-world” figure but it is unlikely to greatly change the ordering of cars in a table of most efficient to least.
I have no sympathy though with any European buyers that are suddenly squawking that they can’t achieve the claimed test mileage.
MPG != emissions testing.
Mileage testing is done in a controlled environment in a very specific way, so that it’s repeatable and comparable between vehicles. As long as the tests (and whatever fudging is allowed) are done within the same tolerances, the tests are comparable, even if they’re not necessarily representative of what that vehicle might get in the real world.
Case in point: the pre-2008 EPA gas mileage figures were repeatable and comparable across vehicles, although not at all representative of real world conditions. The 2008 and later ones are more representative, but still repeatable and comparable.
The Euro manufacturers (and likely the US ones) fudge as much as the tests will allow for mileage calculation purposes.
VW on the other hand, was cheating the emissions testing, which is independent of mileage testing. It’s what’s done when they jam that doodad up the car’s tailpipe and then run it at a specified RPM for some period of time, or they poll the OBD-II info while doing the same thing. VW basically figured out a way to recognize when that testing was occurring and to basically optimize the engine such that it had excellent emissions results under those specific conditions, and then much worse ones in everyday driving, which is not supposed to be the case.