How do u guys calculate miles per gallon?

[GasSavers_fuelmiser]

i appreciate everyone's reply to this thread. thank you! it gives me an idea of everyone's thought process. i didnt know the fuel tank area was so complex. but from what im gathering..i conclude that consistency is the most important variable when filling up.

one thing noone mentioned is...after filling up the tank...go to each four corners of the car and give each corner a couple of bounces to get rid of "Air Pockets"...is this myth true? things that make u go hmmm...