Filling Your Tank
Filling your fuel tank appears to be a very simple task, but there is actually a right way and a wrong way to do it. The correct way is to stop filling the tank when the fuel pump automatically shuts off. "Topping off" the fuel tank, or filling it up to the neck, can impede the vapor canister that collects fuel vapors from the tank. Topping off the tank could also cause you to spill fuel on to ground. This is a waste of money and fire hazard; it also permits the release of poisonous gasoline vapors (hydrocarbons). Furthermore, even if the tank is not overfilled, gasoline may expand on a hot day and force itself out of your tank and on to the ground.