2009 Chevrolet Cobalt Owner's Manual - Page 277

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. Engine Oil Additives/Engine Oil Flushes Do not add anything to the oil. The recommended oils with the starburst symbol that meet GM standards are all that is needed for good performance and engine protection. Engine oil system flushes are not recommended and could cause engine damage not covered by the vehicle warranty. Cold Temperature Operation For Vehicles With the 2.2L L4 Engine If in an area of extreme cold, where the temperature falls below −20°F (−29°C), use either an SAE 5W-30 synthetic oil or an SAE 0W-30 engine oil. Both provide easier cold starting for the engine at extremely low temperatures. Always use an oil that meets the required specification, GM6094M. See "What Kind of Engine Oil to Use" for more information. Engine Oil Life System When to Change Engine Oil This vehicle has the Engine Oil Life System, a computer system that indicates when to change the engine oil and filter. This is based on engine revolutions and engine temperature, and not on mileage. Based on driving conditions, the mileage at which an oil change is indicated can vary considerably. For the oil life system to work properly, the system must be reset every time the oil is changed. 5-19