Im running a jku with 35x12.50xr17 general grabber at2's 3 inch lift with stock 6 speed and 4.88 gears front and rear what can i do to make the gas mileage better. i talked to a guy with stock gears and auto trans but similar set up and he was doing 18 or 19 city while im doing anywhere from 13 to 14

 

Did you recalibrate after putting on 35s? If not, your numbers may be a little off. Also, the guy with the auto may be running a programmer. Driving style is a big factor too, but seriously, you're running a Jeep with 35s, if you're that worried about mpgs, go back to stock or drive something else. Worse mileage should not be a shock.