Gasoline SpecificationsAt a minimum, gasoline should meet ASTMspecification D 4814 in the United States orCAN/CGSB-3.5 in Canada. Some gasolines maycontain an octane-enhancing additive calledmethylcyclopentadienyl manganese tricarbonyl(MMT). General Motors recommends against theuse of gasolines containing MMT. See Additiveson page 350 for additional information.California FuelIf your vehicle is certified to meet CaliforniaEmissions Standards, it is designed to operate onfuels that meet California specifications. Seethe underhood emission control label. If this fuel isnot available in states adopting Californiaemissions standards, your vehicle will operatesatisfactorily on fuels meeting federalspecifications, but emission control systemperformance may be affected. The malfunctionindicator lamp may turn on and your vehicle mayfail a smog-check test.See Malfunction Indicator Lamp on page 208. Ifthis occurs, return to your authorized GM dealer fordiagnosis. If it is determined that the condition iscaused by the type of fuel used, repairs maynot be covered by your warranty.AdditivesTo provide cleaner air, all gasolines in the UnitedStates are now required to contain additivesthat will help prevent engine and fuel systemdeposits from forming, allowing your emissioncontrol system to work properly. In most cases,you should not have to add anything to your fuel.However, some gasolines contain only theminimum amount of additive required to meet U.S.Environmental Protection Agency regulations.To help keep fuel injectors and intake valves clean,or if your vehicle experiences problems due todirty injectors or valves, look for gasoline that isadvertised as TOP TIER Detergent Gasoline. Also,your dealer has additives that will help correctand prevent most deposit-related problems.350
