If your vehicle has a diesel engine, see "Diesel Fuel Requirements and Fuel System" in the DURAMAX® Diesel Supplement.

For vehicles with gasoline engines, please read this.

Gasoline

The 8th digit of your vehicle identification number (VIN) shows the code letter or number that identifies your engine. You will find the VIN at the top left of the instrument panel. See Vehicle Identification Number (VIN) .

If your vehicle has the 5.3L V8 engine (VIN Code Z only), you may use either regular unleaded gasoline or ethanol fuel containing up to 85% ethanol (E-85); also see Fuel E85 (85% Ethanol) . In all other engines, use only regular unleaded gasoline.