The base turbo four-cylinder in A5 models varies quite a bit with choice of transmission and front- or all-wheel drive. The front-drive Cabriolet earns the best gas mileage in the range, at 24 mpg city, 32 mpg highway, and 27 mpg combined. Next is the A5 coupe with quattro all-wheel drive and a six-speed manual transmission at 24 mpg city, 32 mpg highway, and 26 mpg combined--nearly identical, but for the slightly lower combined rating.
Opting for either the A5 Cabriolet with quattro all-wheel drive or the A5 quattro Coupe, when equipped with the automatic transmission yields the same result: 20 mpg city, 29 mpg highway, and 24 mpg combined.
Audi's S5 models get a great deal more horsepower thanks to a supercharged V-6 engine, but also suffer in terms of gas mileage, rating 18/28/21 mpg city/highway/combined with the dual-clutch automatic transmission, or 17/26/20 with the six-speed manual gearbox.
The RS5's 450-horsepower output requires even more fuel, bringing it down to 16 mpg city, 23 mpg highway, and 18 mpg combined.
Though Audi offers hybrids and diesels elsewhere in its lineup, neither technology has made it to U.S. versions of the A5 range.