C 2500 Yukon XL 2WD V8-8.1L VIN G (2002)
Fuel: Description and Operation
FUEL SYSTEM SPECIFICATIONS
Use regular unleaded gasoline rated at 87 octane or higher. The gasoline should meet the specifications developed by the American Automobile
Manufacturers Association (AAMA) and endorsed by the Canadian Motor Vehicle Manufacturers Association for better vehicle performance and engine
protection Gasoline meeting the AAMA specification could provide improved driveability and emission control system performance compared to other
gasoline. For more information write to: American Automobile Manufacturers Association, 7430 Second Ave., Suite 300, Detroit, MI, 48202.
Be sure the posted octane is at least 87. If the octane is less than 87, you may get a heavy knocking noise when you drive. Severe knocking can damage
your engine.
If you are using fuel rated at 87 octane or higher and you hear heavy knocking, your engine needs service. Do NOT worry if you hear a little pinging
noise when you are accelerating or driving up a hill That is normal, and you do not have to buy a higher octane fuel to get rid of pinging. However. a
heavy constant knock indicates a problem.
NOTE: Your vehicle was not designed for fuel that contains methanol. Do not use methanol fuel which can corrode metal parts in your fuel system arid
also damage plastic and rubber parts. This kind of damage would not be covered under your warranty.
If your vehicle is certified to meet California Emission Standards, indicated on the underhood emission control label, your vehicle is designed to operate
on fuels that meet California specifications. If such fuels are not available in states adopting California emissions standards, your vehicle will operate
satisfactorily on fuels meeting federal specifications, but the emissions control system performance may be affected. The malfunction indicator lamp (
MIL) on your instrument panel (IP) may turn ON, and/or your vehicle may fail a smog test. See Malfunction Indicator Lamp in the Index. If this occurs,
return to your authorized GM dealer for diagnosis to determine the cause of the failure. In the event the cause of the condition is the type of fuels used,
repairs may not be covered by your warranty.
Some gasolines that are not reformulated for low emissions may contain an octane-enhancing additive called Methylcyclopentadienyl Manganese
Tricarbonyl (MMT). Ask your service station operator whether or not the fuel contains MMT. General Motors does not recommend the use of such
gasolines. If fuels containing MMT are used, spark plug life may be reduced and your emission control system performance may be affected. The MIL
on your instrument panel may turn ON. If this occurs, return to your authorized GM dealer for service.
To provide cleaner air, all gasolines in the United States are now required to contain additives that will help prevent deposits from forming in your
engine and fuel system, allowing your emission control system to function properly. Therefore, you should not have to add anything to the fuel. In
addition, gasolines containing oxygenates, such as ethers and ethanol, and reformulated gasolines may be available in your area to contribute to clean air.
General Motors recommends that you use these gasolines, particularly if they comply with the specification described earlier.
Fuels in Foreign Countries (Gasoline Engines)
If you plan on driving in another country outside the United States or Canada, the proper fuel may he hard to find. Never use leaded gasoline or any
other fuel not recommended in the previous text on fuel. Costly repairs caused by the use of improper fuel would not be covered by your warranty
To check on fuel availability, ask an auto club, or contact a major oil company that does business in the country where you will be driving.