2004 Dodge Ram 3500 Pickup Owner's Manual - Page 260

260 STARTING AND OPERATING Fuel Filler Cap (Gas Cap) The gas cap is behind the fuel filler door. If the gas cap is lost or damaged, be sure the replacement cap is for use with this vehicle. WARNING! • Remove the fuel tank filler tube cap (gas cap) slowly to prevent fuel spray from the filler neck which may cause injury. • The volatility of some gasolines may cause a buildup of pressure in the fuel tank that may increase while you drive. This pressure can result in a spray of gasoline and/or vapors when the cap is removed from a hot vehicle. Removing the cap slowly allows the pressure to vent and prevents fuel spray. • Never allow any lit smoking materials near the vehicles while removing the cap or filling the tank. • Never add fuel to the vehicle when the engine is running. CAUTION! Damage to the fuel system or emission control system could result from using an improper fuel tank filler tube cap (gas cap). A poorly fitting cap could let impurities into the fuel system.