Fuel mileage? When you have this kind of power, who cares about fuel mileage. Seriously, I made two trips out to the Big Horn Mountains in Wyoming last summer, the first trip was predator on 65 and the second on 40. Both trips pulling the same tailer loaded with ATV's, as seen in my garage. Both trips I got between 11-13 MPG. Other than that, I really don't worry about mileage. I didn't buy this big of a truck with mileage as one of my top concerns. Maybe someone else can shed more light on their findings.