The Audi A7 is a mid-size car with plenty of luxury gear tucked inside—including standard all-wheel-drive. With that on background, the EPA's gas-mileage ratings for the standard supercharged V-6 edition are in line with expectations, at 18 mpg city, 28 mpg highway, and 21 mpg combined.
For the best fuel economy of its kind, however, you'll want to saddle up the new A7 TDI. Its exemplary EPA ratings of 24 mpg city, 38 mpg highway, 29 mpg combined outscore one of its main rivals, the Mercedes-Benz E350 BlueTEC, which is rated at 33 mpg highway.
Audi's use of an eight-speed automatic is one of the more subtle ways fuel economy is so good with these versions. It has a very wide range of gears, including a very tall top gear for low highway cruising revs. In either case, the EPA estimates are within reach for ordinary drivers; we've seen up to 22 mpg combined with the gas-powered car, and in a half-day of TDI cruising, reached its 38-mpg highway rating.
The high-performance S7, with its 420-horsepower turbocharged V-8, is nearly as efficient as the supercharged six, at 17/27 mpg or 20 mpg combined. And even the supremely powerful RS 7 avoids a gas-guzzler tax despite its 520 hp; it's rated at 16 mpg city, 27 mpg highway, or 19 mpg combined
It's worth pointing out that the base A7 manages just 1 mpg better overall than the larger A8 L sedan, which has a considerably roomier interior and much more backseat space.