[kingu]

The mileage calculated by the EPA would have been determined with the "test mode" emissions, so as far as a reduction in mileage, the car will still meet the advertised mileage on the window sticker, so no liability there.

I'm really confused; when did the EPA take over for the National Highway Traffic Safety Administration who I thought still conducted and did the certification for the sticker city and highway MPG numbers? And if the NHTSA still conducts those tests, when did they start doing emissions testing during those exams?

[Yo-Yo]

Do you that for a fact, or are you just speculating? I suspect the test mode is not used for calculating the MPG.

Until we know exactly how the vehicles detected they were being tested and went into test defeat mode, obviously it is speculation on my part. But Government emissions and mileage testing are done at the same facility:

http://www3.epa.gov/nvfel/