Looks like they were turning off parts of the NOx adsorber. Here’s the detailed EPA write-up in VW’s case: http://www3.epa.gov/otaq/cert/documents/vw-nov-caa-09-18-15.pdf
There’s some detail on the detection algorithm:
based on various inputs including the position of the steering wheel, vehicle speed, duration of the engine’s operation, and barometric pressure. These inputs precisely track the parameters of the federal test procedure used for emission testing
I can’t believe they thought no one would notice.
I’m wondering how this was kept quiet for so long - a whole chain of people must have authorized this, implemented it and tested it.
I would guess their moral qualms were allayed by the fact that everybody knows the tests are flawed and everybody cheats. It’s almost like a little game. Get the best number you can given these arbitrary constraints.
It’s not even a simple case of “I know it’s bad, but everybody else does it.” It’s “the test is so divorced from reality and there’s so many ways to cheat, it simply does not matter.”
That said, I think there’s a line crossed between making an engine that happens to be more efficient in a particular range and actively detecting the test. Nevertheless, I also think a test so easily gamed is equally to blame. If you want people to act ethically, don’t entice them to be unethical.
This is getting into politics, but I don’t think corporations should be encouraged to break laws - they write enough of them themselves. The EPA rules apply to all companies. Companies may try to dodge the spirit of the laws by classifying vehicles strategically. Engineers may optimize engine performance in ways simply to follow EPA standards. But to have code that detects when tests are run and operate the engine differently - well I think people should go to jail for that. Like important people who are now busy in the press making statements that sound like apologies but actually aren’t.
Oh, they sure are apologizing—they’re very sorry they got caught.
But yes, heads should roll for this. VW should be assessed the maximum possible $18 billion fine. Unless and until companies are bankrupted by fines and top executives are jailed, having to pay up for breaking the law is just another business expense and companies will keep doing it.
I do find it seriously hard to believe anyone at VW thought they could get away with this, though. Even the slightest hint of a measurement—hell, probably someone sufficiently knowledgeable just sniffing the exhaust—outside a detectable emission test would give the game away immediately. It’s amazing to me they got away for as long as they did (though this announcement has no doubt been working its way through the EPA’s bureaucracy for a while now).
Sounds like Formula 1 :)
I can’t figure out exactly why they would bother to cheat?
Per the article:
Experts in automotive technology said that disengaging the pollution controls on a diesel-fueled car can yield better performance, including increased torque and acceleration.
Little more info on how this came to light.