Tough new CAFE standards in the U.S. had a lukewarm reception when they were announced in April, with most carmakers reluctantly stating they would rise to the challenge. BMW has now come out against the current program, asking the government to develop an alternative system of requirements, because it will not be able to comply with the CAFE standards as they stand.

The proposed CAFE standards announced in April set industry average targets of 35.7mpg for cars and 28.6mpg for SUVs and pickup trucks by 2015. However, since the required economy figures for each manufacturer are calculated on the basis of the car's 'footprint', or the area enclosed by its wheels.

That means BMW would have to meet a fleet-wide fuel economy figure of 37.7mpg by 2015, reports Automotive News. Between now and the final deadline, there will be a number of intermediate milestones to be met. BMW's official comments on the CAFE standards state that as it stands, compliance will not be feasible. Comments from more automakers are expected soon, with the window for comments closing July 1.