Cars coming out in the 2012 model year are going to get graded.

The Department of Transportation and the Environmental Protection Agency unfurled the new window stickers that will grace cars in the near future to better inform prospective customers about their fuel consumption. In a nutshell, the cars get grades. Electric cars will generally get an A+ while plug-in hybrids will get A's.

Regular hybrids -- which will constitute the largest percentage of cars with electric propulsion -- will get A minuses.

Gas-burning cars will then get grades ranging from A minus to D, depending on their mileage. Supercars from Ferrari and a wide variety of SUVs will be sitting in the back of the class.

The ratings have come about in part because it has become difficult to compare the mileage of plug-in cars with all-electric cars. Electricity is measured in kilowatt hours, while gas is measured in gallons. Mileage varies according to how you drive, too. In 2008, there was a comic interlude when Google saw the mileage on its plug-in hybrids jump from the 60-plus-miles-per-gallon range to more than 100. How did they do it? The company hired professional drivers and kept the cars on fixed courses.

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