With those of us driving vans, fueling at the halfway point makes sense for another reason. You have an electric fuel pump in the tank, and keeping fueled up means the pump has to do less work to overcome the pressure head and it keeps the pump submerged in fuel so it runs cooler and stays well lubricated. Running a tank dry is bad business, sooner or later you will burn out the pump that way and then it's an expensive proposition to lower the tank, remove the pump and sender unit and replace them, then raise the tank back into position and replace fuel that had to be removed before lowering the tank. This job is usually too big for the do-it-yourselfer, so that means you'll pay labor charges on top of the cost of parts and the cost of the jobs you couldn't take because your van was down for fuel-pump replacement. Not to mention the cost of the tow-- when the fuel pump quits you're not going anywhere.