If you're shopping for a performance-focused luxury coupe or convertible, you probably don't have your mind set on getting the best mileage in the business. As such, the 2013 Nissan G37 Coupe and Convertible are likely about par among its competitive set—although they're guzzlers compared to some of the latest two-doors from Germany, like the Audi A5 and S5, as well as the BMW 3-Series Coupe models.
The G37 Coupe gets EPA fuel economy figures of up to 19 mpg city, 27 highway, which places it as a bit less efficient than a typical V-6 mid-size sedan. With turbocharged four-cylinders on offer for the new Z4 and SLK, though, this class is becoming more fuel-efficient and green. Last year Infiniti offered the G sedan in a slightly more efficient G25 sedan, but that was never offered in the Coupe and it's already been discontinued in the Sedan.
Expect do do a bit worse in the G37 Convertible, due to its extra weight. With ratings as low as 16 mpg city, 24 highway, the drop-tops average about 1 mpg lower with either transmission.