2. 2016 Audi A6
Gas mileage: 38 MPG (highway)
The 2016 Audi A6 is an extremely fuel efficient luxury car with a 30 MPG fuel efficiency rating for the highway. The auto has a well-apportioned interior, and the stock engine for the car is a 2.0 liter turbo-four cylinder rated at 252 horsepower coupled to a seven-speed automatic transmission with front-wheel drive. Consumers can choose to upgrade to a supercharged 3.0 liter V-6 rated at 333 horsepower combined with an eight-speed automatic transmission and all-wheel drive. The overall gas mileage rating of the automobile is 25 MPG (city) and 38 MPG (highway). The A6 has a top overall speed of 128 MPH, and the auto can go from zero to 60 MPH in just 4.6 seconds.