2009 Jeep Liberty Owner's Manual - Page 370

368 STARTING AND OPERATING of gasoline may not be indicated on the gasoline pump; therefore, you should ask your gasoline retailer whether the gasoline contains MMT. It is even more important to look for gasolines without MMT in Canada, because MMT can be used at levels higher than those allowed in the United States. MMT is prohibited in Federal and California reformulated gasoline. Materials Added To Fuel All gasoline sold in the United States is required to contain effective detergent additives. Use of additional detergents or other additives is not needed under normal conditions and they would result in additional cost. Therefore, you should not have to add anything to the fuel. Fuel System Cautions CAUTION! Use the following guidelines to maintain your vehicle's performance: • The use of leaded gas is prohibited by Federal law. Using leaded gasoline can impair engine performance, and 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 authorized dealer for service assistance.