I can get 18 MPG at 60 MPH with a 261 souped-up a little and a 3.55 rear end and 31.5" diameter tires (my odometer/speedometer is calibrated).
Maybe my rolling box is a little more stream-lined than your rolling box?
Maybe you are quicker off the line?
Maybe you wear out brakes faster than I do?
Maybe this is just another unexplainable mystery of life?
Let's hope we hear from the guy who gets 38 MPG with a 292 - he knows something that none of us knows?
