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 the use ofgasolines containing MMT. See Additiveson page 5-6 for additional information.California FuelIf your vehicle is certified to meet California EmissionsStandards, it is designed to operate on fuels thatmeet California specifications. See the underhoodemission control label. If this fuel is not availablein states adopting California emissions standards,your vehicle will operate satisfactorily on fuels meetingfederal specifications, but emission control systemperformance may be affected. The malfunctionindicator lamp may turn on and your vehicle may faila smog-check test. See Malfunction Indicator Lampon page 3-42. If this occurs, return to your authorizedGM dealer for diagnosis. If it is determined that thecondition is caused by the type of fuel used, repairsmay not be covered by your warranty.AdditivesTo provide cleaner air, all gasolines in the United Statesare now required to contain additives that will helpprevent engine and fuel system deposits from forming,allowing your emission control system to workproperly. In most cases, you should not have to addanything to your fuel. However, some gasolines containonly the minimum amount of additive required tomeet 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, yourGM dealer has additives that will help correct andprevent most deposit-related problems.Gasolines containing oxygenates, such as ethers andethanol, and reformulated gasolines may be available inyour area. General Motors recommends that you usethese gasolines if they comply with the specificationsdescribed earlier. However, E85 (85% ethanol)and other fuels containing more than 10% ethanol mustnot be used in vehicles that were not designed forthose fuels.5-6
