It's a supercar...what? You were expecting fantastic fuel economy from a 571-horsepower two-seater?
It's not as terrible as it could be, though. The 2012 Mercedes-Benz SLS AMG--in either body style--is rated at 14/20 mpg by the Environmental Protection Agency. We've seen far worse from Lamborghini, and even the superhero Nissan GT-R barely bests these numbers.
The SLS' clean and green credentials could be issued as early as 2013, however, when Mercedes puts the finishing touches on an all-electric version of the AMG supercar. Benz promises performance equal to that of the gas-powered SLS, but the new "E-Cell" version may have a total driving range of less than 50 miles, if that's the case.