[ronnietherocket3]

Pretty simple answer: either test properly, or get rid of the regulation. The university that found the “cheating” tested properly under real world conditions. The official government testers did not. For that they need to be fired.

The generic problem that you run into is determining whether a real world test has so much variability in it that one car may fail when it should otherwise pass or pass when it should otherwise fail. The only way out of this issue is to have a test like the current ones and then randomly monitor vehicles and if a particular model falls too far outside of specs, investigate.

[palmer]

That is not the only way out. We can forget about tests, let the private sector sort it out. Or make the government bureaucrats define realistic regulations or be fired. Or force car makers to install calibrated sensors that can be easily tested.

If NOx were a problem we would pick #3. But it is not, it is a fake problem.