Our ’95 F-150 had 17 & 18 gal fuel tanks with a switch to change tanks and the fuel gauge. One had to stay cognizant of the “off” tank to keep from getting caught with too little fuel. When we went from a 27’ fifth wheel to a 37’ we swapped out the OEM 26 gallon tank (Super Duty short bed) for a 50 gallon Titan replacement purely for convenience. We’re not worried about the cost of the tank or saving fuel cost, although the larger tank does allow a little flexibility on fuel prices. With the old small tank we sometimes had to fill before the ¼ point because it was too far to the next acceptable fuel stop. Next truck (if there is a next truck) will definitely be a long bed Ford with a 48 gallon stock tank.