The test is accurate and measures emissions very well. The cars emit NOX at levels lower than the legal limits during the test. There is no mistake during the test and no cheating (apart from VW).<p>However, when the cars are used by normal drivers, the usage patterns are so significantly different than the test sequences that the emissions profile changes. In the majority of cases the NOX emissions from cars used by normal people exceed the EU limits.<p>This does not, as I understand it, mean that the cars are illegal. The cars all passed the tests in the test environment. That is the requirement and they met the requirement.<p>No law is being broken but that is only because the law is not fit for purpose.