Mallard, you must not fully understand how tank gauges work. I don't mean to bash but it is not a linear relationship, meaning if your gauge says you have 1/4 tank left, you really only have about 1/6. They drop really slow to start with then they speed up just as you run out. This has a psychological effect that makes the driver fill up less and not keep the gas tank full. Auto manufacturers purposely do this for a couple reasons...If everyone kept their tank full, we would have a gas "shortage problem" similar to what happened in the late 70s. Second, more gas means more weight to the vehicle (5 gallons is close to 48 lbs).