Ran out of gas

I normally fill up when the fuel light comes on and I usually end up pumping around 3.5 galllons. After doing this time after time I figured I could go a little longer before fueling. Well I ran out of gas today, it started sputtering and I knew what was happening. Luckily, it died at the top of a hill and there was a gas station at the bottom. I started it up a couple of times and got an extra 10 feet out of it each time. After "topping it off" I had pumped exactly 4 gallons. I THOUGHT THESE THINGS HAD 5 GALLON TANKS??!! :(" title="" border="0"/> ??? don't piss off the wolf.