I've got a 2007 Sahara 2dr automatic that came with 4:10 gears from the factory. After lifting and 35 in tires, the ride has been bearable around town, but highway was less than desirable. I have noticed from a start the rpm's revving pretty high to get up to speed. And that's with a lot of foot on the gas pedal. So, on a guess, I set my pro cal for 4:10 gear ratio, and reprogrammed my jeep. The difference is night and day in a good way. Less throttle to get up to speed, less down shifting, and much better at freeway speeds. As a result, mpg's seem to have improved significantly, although that's not much of a concern. So, my question is, should the change have been so noticeable, or is it all in my head? I know the 4:10 gears are still not optimal for my setup, but there seems to be much improvement due to the recal.