The EPA doesn't test every car. They usually certify the manufacturer's numbers and test a subset of models. Further according to the EPA website, the vehicle they test is usually a pre production prototype to avoid delays of vehicles to market.
The one thing that may mess up this smooth process is that in 2012 they tested the 550xi which had already been certified in 2011 using BMW numbers, and they found that BMW overstated the mpg by about 4mpg. So maybe they are now treating BMW with higher scrutiny.
|