2010 Chevrolet HHR Owner's Manual - Page 324
2010 Chevrolet HHR Manual
Page 324 highlights
For Vehicles with the 2.0L L4 Engine Only Look for three things: . GM4718M This vehicle's engine requires a special oil meeting GM Standard GM4718M, such as Mobil 1® or equivalent. 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. 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). 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. This vehicle's engine was filled at the factory with a 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. . American Petroleum Institute (API) starburst symbol 6-22