Rear-End Gear Ratios

[Magard]

ZeroNthedark. I have thought things like this before. But when you ran the numbers. I was wrong. Day in and day out. Pushing 70 mph wind costs more. Is like driving into a head wind or tail wind. Out west on the big roads if you have a tail wind you can get decent mpg going with the wind at 70. Turn around and go 60 into the wind and your getting worse mileage. Maybe rawze can chime in, I used to think some of the early emission engines kinda quite the emission mode above a certain rpm and work load. But I had know way of knowing. I do know that 70 is a hard push.