1998 Chevrolet Prizm Owner's Manual - Page 230

Be sure the posted octane at least 87. If the octane is is less than 87, you may get a heavy knocking noise when you drive. If it's bad enough, can damage your engine. it 87 If you're using fuel rated at octane or higher and you hear heavy knocking, your engine needs service. But don't worry if you hear a little pinging noise when you're accelerating or driving up a hill. That's normal, and you don't have to buy a higher octane fuel to get rid Some gasolines that are not reformulated for low of pinging. It'sthe heavy, constant knock that means emissions contain an octane-enhancing additive called you have a problem. methylcyclopentadienyl manganese tricarbonyl (MMT); If your vehicle is certified to meet California Emission ask your service station operator whether or not his fuel contains MMT. General Motors does not recommend the Standards (indicated on underhood emission control the MMT are used, use of such gasolines. If fuels containing label), it is designed to operate on fuels that meet spark pluglife may be reduced and your emission California specifications.If such fuels are not available may be affected. The in states adopting California emissions standards, your control system performance malfunction indicator lampon your instrument panel vehicle will operate satisfactorily on fuels meeting may turn on. If this occurs, return to your authorized federal specifications, but emission control system Chevrolet dealer for service. performance may be affected. The malfunction indicator lamp on your instrument panel may turn on and/or your vehicle may fail a smog-check test. this occurs, return If to your authorized Chevrolet dealer for diagnosis to determine the cause failure. In the event it is of determined that the cause of the conditionthe typeof is fuels used, repairs may not be covered your warranty. by 6-4