I drive a "fleet" GT with no supercharger and get about 320 miles on a tank before I look for a gas station. Usually the DIC and the fuel gauge show I could go another 30-50 miles. So 26-30 mpg. Not bad considering I have added a of weight to the car in gear in the trunk, heavier wheels and suspension upgrades. Great car, wish they were still made, would buy two more. Looking for a GXP local to me now.