GM Service Manual Online
For 1990-2009 cars only

The fuel must meet ASTM Standard: D4814 (U.S.), CGSB 3.5-M93 (Canada).

Octane Requirements

4.0L (VIN C)

Min. Octane Requirement: 91 [(R+M)/2] (pump) octane, where R= research octane number, and M= motor octane number.

Gasoline with Alcohol

Notice: Do Not spill fuel containing alcohol on the vehicle. Alcohol can cause damage to the paint finish and the trim.

Methyl Tertiary-Butyl Ether (MTBE)

Fuel containing Methyl Tertiary-Butyl Ether (MTBE) may be used, providing there is no more than 15% alcohol by volume.

Ethanol

Fuel containing ethanol (ethyl) or grain alcohol may be used, providing that there is no more than 10% ethanol alcohol by volume.

Methanol

Notice: Do not use fuels containing methanol in order to prevent damage and corrosion to the fuel system.

Methylcyclopentadienyl Manganese Tricarbonyl (MMT)

If a vehicle is certified to meet California Emission Standards (indicated on the under-hood tune-up label), it is designed to operate on fuels that meet California specifications. If such fuels are not available in states adopting California emissions standards, a vehicle will operate satisfactorily on fuels meeting federal specifications, but emission control system performance may be affected. The malfunction indicator lamp on the instrument panel may turn on. The vehicle may also fail a smog-check test.

Some gasolines that are not reformulated for low emissions contain an octane-enhancing additive called methylcyclopentadienyl manganese tricarbonyl (MMT). General Motors does not recommend the use of such gasolines. If fuels containing MMT are used, spark plug life may be reduced, and emission control system performance can be affected. The malfunction indicator lamp on the instrument panel can turn on.

To provide cleaner air, all gasolines are now required to contain additives that will help prevent deposits from forming in the engine and fuel system. These additives will allow the emission system to function properly. Therefore, there does not need to be anything added to the fuel. In addition, gasolines containing oxygenates, such as ethers and ethanol, and reformulated gasolines may be available in the area to help clean the air. General Motors recommends that the above mentioned gasolines be used if they comply with specifications described earlier.