1998 Pontiac Bonneville Owner's Manual - Page 255

If you have the3800 Supercharged engine(VIN Code l), use premium unleaded gasoline rated at octane 91 or higher. With the3800 Supercharged engine, inan emergency, you may be able to use a lower octaneas -If low as 87 -- if heavy knocking does not occur. you are using91 or higher octane unleaded gasoline and you hear heavy knocking, your engine needs service. At a minimum, the gasoline you use should meet specifications ASTM D4814 in the United States and CGSB 3.5-M93 in Canada. Improved gasoline specifications have been developed by the American (AAMA) for Automobile Manufacturers Association better vehicle performance and engine protection. Gasolines meeting theAAMA specification could provide improved driveability and emission control system protection compared to other gasolines. Be sure the posted octane for premium least91 (at is at least 89 for middle grade and for regular).I the 87 f octane is less than you may get a heavy knocking 87, noise when you drive. If it's bad enough, can damage it your engine. If your vehicleis certified to meet California Emission Standards (indicated on the underhood emission control label), it is designed to operate onfwels that meet California specifications.If such fuels are not available in states adopting California emissions standards, your vehicle will operate satisfactorily fuels meeting on federal specifications, but emission control system performance may be affected. The malfunction indicator lamp on your instrument panel may on and/or your turn vehicle may fail a smog-check test.this occurs, return If to your authorized Pontiac dealer for diagnosis to In determine the cause of failure. the eventit is determined that the cause of the condition the type of is fuels used, repairs may not be covered by your warranty. for Some gasolines that are not reformulated low emissions containan octane-enhancing additive called methylcyclopentadienyl manganese tricarbonyl(MMT); ask your service station operator whether or his fuel not contains MMT. General Motors does not recommend the use of such gasolines. If fuels containingMMT are used, spark plug life may be reduced and your emission control system performance may be affected. The malfunction indicator lamp your instrument panel on may turn on. If this occurs, returnto your authorized Pontiac dealer for service. 6-4