I have a new Honda Civic Hybrid and I am trying to figure out just how accurately the electronic gauge displays mileage per gallon. Please excuse me for posting here but I didn't get much info from the Honda group so I am trying here because Cadillacs have had electronic fuel computers for quite some time. I've always calculated mpg whenever I fill the tank. I know that the calculations have error/variation since the gas pump cut-off won't always fill the tank to the same level so the amount of gas used is off. When I compare the fill-up calculations to the electronic gauge readings, they are always different sometimes by almost 2 mpg (both higher and lower). I assume the gauge uses some kind of flow meter sensor which I hope it is more accurate in determining gas used than the pump fill-up method.
Would appreciate any comments/info on Cadillac computer accuracy which could be similar to my Honda. Also curious to know just how these gauge and sensors work. Thanks -V