2009 Chevrolet Corvette Owner's Manual - Page 301

What Kind of Engine Oil to Use Look for three things: Notice: Using oils that do not have the GM4718M Standard designation can cause engine damage not covered by the vehicle warranty. • SAE 5W-30 SAE 5W-30 is best for the vehicle. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils such as SAE 20W-50. American Petroleum Institute (API) starburst symbol Oils meeting these requirements should have the starburst symbol on the container. This symbol indicates that the oil has been certified by the American Petroleum Institute (API). • • GM4718M This vehicle's engine requires a special oil meeting GM Standard GM4718M. Oils meeting this standard may be identified as synthetic. However, not all synthetic oils will meet this GM standard. Use only an oil that meets GM Standard GM4718M. This vehicle's engine was filled at the factory with a Mobil 1® synthetic oil meeting all requirements for this vehicle. Substitute Engine Oil: When adding oil to maintain engine oil level, oil meeting GM Standard GM4718M might not be available. You can add substitute oil designated SAE 5W-30 with the starburst symbol at all temperatures. Substitute oil not meeting GM Standard GM4718M should not be used for an oil change. 5-25