2006 Chrysler PT Cruiser Owner Manual - Page 324

324 STARTING AND OPERATING MMT In Gasoline MMT is a manganese containing metallic additive that is blended into some gasoline to increase the octane number. Gasolines blended with MMT offer no performance advantage beyond gasolines of the same octane number without MMT. Gasolines blended with MMT have shown to reduce spark plug life and reduce emission system performance in some vehicles. The manufacturer recommends using gasolines without MMT. Since the MMT content of gasoline may not be indicated on the pump, you should ask your gasoline retailer whether or not his/her 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 gasolines. 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 would result in additional 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