With the Memphis Fats on I usually get to 128- 140 miles before I switch to reserve, depending on speed. With it off it's 140- 150. With another gallon on reserve, add another 30 miles before I'm desperate. I usually start looking for gas within 10 miles of switching to reserve. I put the 89-91 octane ethanol blend in because it's several cents cheaper here. I have an 03 TBA with about 17,400 miles on it.