What method/formula do you use to calculate fuel use/mileage?
i started off with a calculator, then some fuely
it all points to the onboard mpg within a few tenths
so i am only using the onboard now
i do a quick math check at each fillup in my head
(335.x miles/ 9.7xx gallons) is close enough to 33.5mpg for me (its actually 34.5)