[KingLT1]

Oil is oil...you have 3 blends. Regular dino, blended, and Synthetic. Well, I guess you could say 4 with break-in oil. Either way, if it's API cert it doesn't really matter the brand. Changing the oil more frequently than the OLM suggests makes a much bigger difference vs oil viscosity. Direct Injection dilutes oil faster than port. Going longer than 5k miles before changing oil is the biggest issue. Gm is just making excuses with the suggestion for 0-40. I am not saying it's bad, but it's not doing anything more over 5w30. For a road course car where the engine is going to get the oil much hotter than street use, I could see a case for using 0-40. But this is really just a band-aid when they should be recalibrating the OLM systems and suggesting shorter oil change intervals imo.