2004 Jeep Liberty Owner's Manual - Page 261

STARTING AND OPERATING 261 CAUTION! DO NOT use gasoline containing METHANOL. Gasoline containing methanol may damage critical fuel system components. MMT In Gasoline MMT is a manganese containing metallic additive that is blended into some gasoline to increase octane. Gasoline blended with MMT provides no performance advantage beyond gasoline of the same octane number without MMT. Gasoline blended with MMT reduces spark plug life and reduces emission system performance in some vehicles. The manufacturer recommends that gasoline without MMT be used in your vehicle. The MMT content of gasoline may not be indicated on the gasoline pump, therefore, you should ask your gasoline retailer whether or not his/her gasoline contains MMT. It is even more important to look for gasoline without MMT in Canada because MMT can be used at levels higher than allowed in the United States. MMT is prohibited in Federal and California reformulated gasoline. Sulfur In Gasoline If you live in the northeast United States, your vehicle may have been designed to meet California low emission standards with clean burning, low sulfur, California gasoline. Gasoline sold outside of California is permitted to have higher sulfur levels which may affect the performance of the vehicle's catalytic converter. This may cause the "Malfunction Indicator Light" to illuminate. Illumination of this light while operating on high sulfur gasoline does not necessarily mean your emission control system is malfunctioning. The manufacturer recommends that you try a different brand of unleaded gasoline having lower sulfur to determine if the problem is fuel related prior to returning your vehicle to an authorized dealer for service. 5