So we turned in a 5 day rental into Avis @ DCA today & I checked the emailed receipt when I landed at our destination about 6 hours later.

It added a $80.71 fuel surcharge for not filling up. Allegedly 23.0 Gal out - 5.5 Gallon in, so 17.5 total Gallons @ 5.039/Gal. The rub is I spent about $65 filling up the car 2 blocks from the lot before we turned it in!!! I guess the electronic sensor in the fuel tank had not updated their system yet?

Any feedback on whether their system will "catch up" & fix the issue, or will I have to "fight" the charge? We didn't keep the receipt for the gas station but will have the credit card statement as proof of location/date for fuel up when the transaction posts.