I used to get real shitty mileage in my 3.4 auto, I used to be happy with 225 miles to a tank. After going back to 265-70s and using the gas better, I'm gettin over 300 per tank and about 19MPG. I'm happy with that. On the way back from the Beach I went through a whole tank almost and the light came two days ago and I'm on 275 miles a tank, but I did about 85 MPH average on the way home for 250 miles.