Thank you for that, and yes you are correct, however I am talking about what the
scangauge reads... When I do an entire fillup the
scangauge registers the proper gallons of gas used to usualy one tenth. However if I have to do a partial fill due to economics lets say and I add 5 gallons, the scangauge reads it as a 9 or 10 gallon fillup and if you adjust it to reflect the proper amount of fuel the readout settings go hay wire.
I know this because there is no way in hell that my xD was averaging 97 miles per gallon on my commute home ... lol Would have been nice, but not true.