Bought an old Dodge van, went to this nearby Am Pm gas station to fill up. Pump showed 30.5 gallons pumped. Tried to find out on line & other sources just how big my tank was, no luck. Bought gas from them for about 1 year, figured I had a 30 gal. tank. Then began buying gas elsewhere at different places, imagine my surprise when none of those places pumped more than 19 gallons at one time! I usually wait until nearly empty before buying gas. Just recent I bought an Isuzi and know it has only a 20 gallon tank, but that am pm pump showed I took 28 gallons! I've used different pumps there, so it's not just one pump. Anybody else ever notice this?