Cars With Best Gas Mileage 2025. Gobankingrates spoke with alan gelfand, owner of german car depot in hollywood, florida, to find out what used cars have the best gas mileage. The overall average combined mpg of cars in 2020 reached 25.7 mpg, a record high, according to the u.s.

19 rows best and worst fuel economy. The overall average combined mpg of cars in 2020 reached 25.7 mpg, a record high, according to the u.s.