I can never fill my tank completely?

[yarisitis]

So I was at the gas station with my girlfriend and she was filling up her 2000 Echo. The tank was almost empty and the gas marker was just above the E. So when she finished filling up I noticed that the pump had stopped at 10.x gallons, and I realized that I'm never able to fill up my 2008 Yaris with that much gas.

Every time I fill my tank up, the pump always stops at around 7 to 8.5 gallons. At times I've driven with the last blinking gas bar for 15-20 miles and fill up thinking that my tank is nearly empty, and the pump still stops at around 8.5 gallons. Why is it that I can't seem to pump more gas than that?

I've always wondered how some of you get 400+ miles on a tank of gas and 80+ miles on the first gas bar, and now I'm thinking it's because you guys fill your tanks up almost completely to the 11 gallons. I usually get around 320-340 miles on a tank and am now thinking that I get that little because I'm only filling up with around 7-8 gallons.

What gives?