When I was in college I bought gas at the same station a lot before heading home or after getting back into town. I pumped 28 gallons and change according to the pump into my half ton chevy that had a 26 gallon tank. I walked inside and told the attendant I wasn't very pleased I could fit 28 gallons in my 26 gallon tank. Not sure if they ever did anything or not.

There's a little sticker on each pump that gives you a number to report this. They will send you a followup once it has been tested.

Really! Just wanted him to check his gas can before he called. Like others said I know how many gallons it takes to fill up my tank. There are several variables on some stations such as a sloping surface. At one station near my house I can get in an extra gallon or one less depending on which side of the pump I fill from.

But it is offset by the guy that fills up after you with Reg Unleded. That guy is getting bonus octane.

Dept. of Agriculture monitors these pumps and they have a date on their sticker. If pumps are off and they get checked, Dept. of Ag. shuts them down. As complicated as those pumps are now, I doubt you are going to find any buffoons working at the store that can "jigger" the pumps. A chain might have their own pump mechanics that could jigger them, but as closely as people watch their fuel and check their mileage, I would not think that it would turn out to be very profitable.