Fuck man, I had gotten literally just one gallon extra when gas prices were rising a while back, and tried to put it in the car. Fucking tip had to be pressed just right, but there was nothing to press it against correctly, kept slipping. Holding with hand gets gas on you. Then once you've got the damn thing carefully positioned to keep it pressed, it takes forever to empty. Spent ten minutes putting a fucking gallon of gas into the car. At least with one of those you won't be dipping into your reserve unless you absolutely need it.