If your vehicle is still under warranty, ONLY change the oil at the dealer. General Motors will look for any excuse not to honor a warranty should you have a problem with your engine. Modern engines are extremely complex in order to squeeze out a little bit more gas mileage. The modern engine, is not designed for long life, they are designed for maximum gas mileage and to limp across the warranty period.Just curious where people are getting the diesel oil changed? I’ve used the dealer 2x now, which is atypical for me (usually 30-50% more for standard oil changes there). But with the diesel, I feel like I’d rather use the dealer. I called Goodyear and Firestone. Goodyear had no idea “we’ve never done one”, and Firestone said $200, which is $40+ higher than the dealer. I’m not interested in a DIY for the diesel. It is a small benefit to have the maintenance records in the GM system.