2007 Chrysler Aspen Owner's Manual - Page 314

314 STARTING AND OPERATING Materials Added To Fuel All gasolines sold in the United States are required to contain effective detergent additives. Use of additional detergents or other additives is not needed under normal conditions and would result in unnecessary cost. Therefore, you should not have to add anything to the fuel. Fuel System Cautions CAUTION! Follow these guidelines to maintain your vehicle's performance: • The use of leaded gas is prohibited by Federal law. Using leaded gasoline can impair engine performance, damage the emission control system. • An out-of-tune engine, or certain fuel or ignition malfunctions, can cause the catalytic converter to overheat. If you notice a pungent burning odor or some light smoke, your engine may be out of tune or malfunctioning and may require immediate service. Contact your dealer for service assistance. • When pulling a heavy load or driving a fully loaded vehicle when the humidity is low and the temperature is high, use a premium unleaded fuel to help prevent spark knock. If spark knock persists, lighten the load, or engine piston damage may result. • The use of fuel additives which are now being sold as octane enhancers is not recommended. Many of these products contain high concentrations of methanol. Fuel system damage or vehicle performance problems resulting from the use of such fuels or additives is not the responsibility of the manufacturer.