2011 Chevrolet Express 1500 Cargo Owner's Manual - Page 279
2011 Chevrolet Express 1500 Cargo Manual
Page 279 highlights
Vehicle Care This certification mark indicates that the oil has been approved to the dexos specification. If you are unsure whether the oil is approved to the dexos specification, ask your service provider. Use of Substitute Engine Oils if dexos is unavailable: In the event that dexos‐approved engine oil is not available at an oil change or for maintaining proper oil level, you may use substitute engine oil displaying the API Starburst symbol and of SAE 5W-30 viscosity grade. Use of oils that do not meet the dexos specification, however, may result in reduced performance under certain circumstances. Viscosity Grade SAE 5W-30 is the best viscosity grade for the vehicle. Do not use other viscosity oils such as SAE 10W‐30, 10W‐40, or 20W-50. 10-9 This vehicle was filled at the factory with dexos‐approved engine oil. Notice: Use only engine oil that is approved to the dexos specification or an equivalent engine oil of the appropriate viscosity grade. Engine oils approved to the dexos specification will show the dexos symbol on the container. Failure to use the recommended engine oil or equivalent can result in engine damage not covered by the vehicle warranty.