Quote:
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Originally Posted by CanAutM3
Quote:
Originally Posted by Jason
Regulators are subjecting diesels to additional testing because of the ongoing scandal over Volkswagen diesels. VW admitted last fall that it rigged some 11 million diesel-powered vehicles worldwide with defeat device software that turns emissions controls on only when the vehicle senses it’s being tested. In regular driving, the systems turn off, which boosts engine performance and fuel economy but permits up to 40 times the legal limit of pollution.
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...for one type of pullutant under WOT conditions !!
While what WV did certainly is not an acceptable practice, people make it sound worse that what it actually is.
We're driving an Audi A4 diesel while on vacation in Europe averaging 4.8l/100km. Quite amazing. It's funny how the EPA does not factor the pollution generated by the disposal of hybrid vehicles' batteries  . |
Not under WOT but under test cycle conditions.
There is no legal limit for WOT conditions. EVERY diesel engine emits much more than 40 times the legal limit under WOT conditions... Pollution limits is only regulated for the test cycle criterias. Outside of the test cycle conditions there are no specific limits. So the legal limit is based on pollution under a quite mild test cycle which has no WOT scenarios at all. Pollution control can't be turned off and the regulators idea is that this will make sure pollution is limited. Problem is that manufacturers use different strategies, or ethics, outside test cycle operation. German authorities did a huge real world and laboratory test of most diesel cars after the VW scandal. Many manufacturers have a extreme increase in pollution as soon as the car is driven outside the test cycle. Usually due to engine mapping and not caring about pollution outside the official test parametres. While others, incl BMW I believe, have a linear increase in pollution in relation to load on the engine.
But, the VW problem was that some models had as much as a 40 fold increase of NOX pollution under normal conditions, as well as test conditions, when the cheat program wasn't activated.... With the amount of VW diesels sold in Europe, the effects on air quality in cities due to the increased amount of nox above legal limits is actually a real concern and not just a theoretical and legal problem..