Mike R said:OK, so this was my second tank doing the speed limit, cruise on 90% of the time. 95% Highway miles. 339 miles on 9.3 gallons. 36.45 MPG. You will get better milage going easy on it. The way I drive now the car doesn't see over 3K RPM. Usually around 2400-2700RPM. I've got a CAI, header, and muffler.