German automaker BMW is probably not the most joyful camper at this time. The mpg fuel-economy rating for its 328i automatic design has been reduced by the Environmental Protection Agency. The ratings slash comes following the EPA's own battery of tests. Well, automakers are expected to a series of tests such as making every new model undergo through a battery of strictly prescribed tests and report the results to the EPA before receiving an official fuel-economy rating. And without any questions from the automakers, the agency will accept the figures. But there are times that the EPA will conduct its own tests. The lowered numbers are a result of that second round of tests by the federal regulation agency. I read this here:
BMW 328i gets EPA fuel economy downgrade.