One of BMW's cars doesn't pass European emissions tests
businessinsider.com
businessinsider.com
We can probably be confident that power plants aren't cheating, because they're so few in number and are therefore much easier to monitor. And we can be highly confident that solar, wind, nuclear, hydro, etc. aren't lying about their emissions.
But it’s certainly easier to monitor a few thousand smokestacks than 200 million cars.
[0] http://www.researchgate.net/profile/Luc_Pelkmans/publication...
a) some cars have are equipped with defeat devices.
b) some cars shouldn't have passed the emissions tests.
c) all the cars emit much more NOx and fine particles than the European Environment Agency and the manufacturers claim.
http://www.bloomberg.com/news/articles/2015-09-24/vw-cheatin...