Obama's Mileage-High Ambition

While this threshold is certainly not outside the realm of possibility (see Chevrolet Volt), any prospect for Detroit's Big Three to meet the President's expectations requires that the companies shift gear and spend millions more on R&D, writes John Broder of The New York Times.

Domestic auto manufacturers also face another, perhaps more challenging, hurdle:

"The automakers say the standard is technically achievable. But they warn that it will cost billions of dollars to develop the vehicles, and they express doubt that consumers will accept the smaller, lighter - and in some cases, more expensive - cars that result."

He continues, "The standard would put domestic vehicle fuel efficiency on a par with that in Europe, China and Japan, saving consumers billions of dollars at the pump and creating for the first time a truly global automobile market."

Due in September, the three agencies that are responsible to implement these regulations are the EPA, the National Highway Traffic Safety Administration, and the California Air Resources Board.