According to the OLM on my 2010 Cobalt, it should go to 9k before an oil change is required. I’m not comfortable with that interval. I normally go 4k between changes, but I’m going to go to a 5k interval for this car with about 45% oil life remaining.
I have to wonder about the contribution of GM marketing department to the development of the OLM algorithm, i.e. to lengthen the interval for marketing purposes. Probably the same people who gave us Dexcool with it’s 5yr/150k interval. The Cobalt doesn’t have a change interval for the auto trans fluid for Normal Service (50k for Severe service). I have a higher regard for OK4550’s opinion over GM or any other auto manufacturer.
Do whatever oil change interval you’re comfortable with, but remember to check the oil level on a weekly basis.
Ed B.