There is much discussion on what is best for your engine and automobile in general when it comes to fuel. The discussion is still not settled. The primary issue is how full to fill your tank. Several only fill it half way, others top off, yet others let it run dry. Regardless of what method you choose, unless you need a personal loan to fix your problems, I suggest studying the flaws with each approach. Topping off may provide you with a few more miles between filling at the pump, however, you run the risk of wrecking your filter that is needed to transfer the gas to make your auto run. Over time, gunk forms on the bottom of your vehicle's gas tank and the ultimate way to clean that out is to let it run extremely low; but if you do not know how to do that you could run it entirely dry and fry your entire engine. People often only fill a tank midway to save on the weight gas causes, but it is such a small difference it might not be worth the headache.