P128sniper

So I was really low on gas today, my approximate miles on display was almost at 0, and when I tanked up I put in 14.1 gallons in and the line went past the full mark. So that means there was still about 2 or more gallons left when the approximate miles showed 0. So when calculating my mpg (assuming I tank up next time when it hits 0 again) meaning I would still have about the same (2 or so gallons) left in the tank, i would divide how many miles I drove by 14.1 instead of 17 gallons correct? So if you guys are doing the same (tanking up when it displays 0, are you guys diving by 17 or the actual amount u used? Am I correct here lol. So I was assuming my mpg was about 14.7 (250 miles driven on tank divided by 17 is only 14.7, but divide it by 14 or 15 it actually give you 17 or 18 mpg..

Bichon

To manually calculate MPG, don't use the trip computer at all. Just reset the trip odometer when you fill the tank. When you fill up again, just divide the number of miles on the trip odometer by the number of gallons it takes to fill the tank.

The accuracy of this method to measure of MPG of a single tank is constrained by the fact that the gas nozzle may click off at slightly different times each fill up, but if you use this method and average your results over several tankfuls, you'll end up with a very accurate number.

P128sniper

Oo ok i get u, so I'm not gonna divide by 14.1, which is what I filled up this tank, I'm gonna do divide by how many gallons I talk up next time to make it a full tank...