The best mileage I have ever got was on a 560 mile trip at 68 to 75 MPH. I had just had a fresh synthetic oil change and a set of plugs and wires. 32 MPG(US) for the trip. Most of the time I get 25MPG(US). Since I got 18 MPG(US) in my 1974 Ford Brougham with a 450 cu inch engine, I consider this to be atrocious. I only do about 10,000 miles a year and the cost to operate is 54 cents a mile. I think I will be returning to a larger car in the future.