I used to have a spreadsheet as well, with fancy formulas that calculated what kind of gas (87 vs 93) got me better MPG in my Honda CRX and the cost per mile. Fuelly is way easier, although I can't seem to link the Android app to my account, so I've been opening the actual webpage on my smartphone and entering the fuel-ups that way.
Thought about adding my 3rd vehicle, a '93 BMW 740il, but would probably vomit as the gas mileage in that tank.
__________________
|