Hi all. This isn't a complaint about gas mileage. I bought a used 2012 S a few months ago, and have been through several tanks of gas now. I'm getting about 16.5 mpg in pretty bad stop and go city driving, and a little shy of 21 mpg going around 75 on the highway. That's pretty solid, and probably because the truck is still bone stock and a manual transmission. The weird thing is, my gauge seems to go down faster than it should be. At around the halfway mark, I can fill the tank with 8 gallons. When the light comes on, I can fill it with about 17 gallons. My manual says I've got a 21.5 gallon tank. Are there 4 gallons below the Empty line? Is this weird, or normal? I'll concede that it's not the worst problem to have, but I just want to make sure it's not a sign of anything that might go wrong.