Among the gasoline versions of the 2012 BMW 7-Series, there's a relatively narrow spread in EPA ratings—that is, until you get to the more efficient 740 or ActivHybrid 7 models.
The best numbers are generated by the six-cylinder Bimmers. The 740i and the 740Li both sport an eight-speed automatic, which helps them achieve gas-mileage numbers of 17/25 mpg, tops in the 7er fleet. And it's worth considering that these are sedans that can very comfortable carry four adults and their luggage, cross-country.
Right behind them is one of the most expensive and complex 7-Series sedans, the ActiveHybrid 7. Like the six-cylinder cars, it comes in a choice of short- and long-wheelbase editions, and both are rated at 17/24 mpg.
From there, fuel economy slides more perceptibly. In the V-8-powered, rear-drive, short-wheelbase 750i, gas mileage is set at 15/22 mpg. Adding a few inches to the wheelbase tips the scales heavier, which trims the numbers to 14/22 mpg in the 750Li.
Adding all-wheel drive to the stock V-8 sedans exacts its own penalty, with the 750i xDrive and 750Li xDrive both earning EPA ratings of 14/20 mpg.
The same 14/22 mpg rating is applied to both the short- and long-wheelbase twin-turbo Alpina B7, the high-performance edition of the 7-Series.Finally, at the low end of expectations, the V-12-powered 760Li checks in at a not unrespectable 13/19 mpg.