Mileage has to do with many factors. Driving style has a lot to do with it...given the mechanics are in good condition, tires are properly inflated, etc. The more highway miles the better the mileage as the stop and go kills the average. That's just my 2 cents worth. I check my mileage at every fill up...and do the math. My old Toyota had a computer that gave you an average MPG...but it was never close when the math was done. I had kids argue that the computer was more reliable...math must have not been their subject in school. Do the math...