Before I had a shared garage with my dad I used to always take my vehicle's to a shop/quick lube to get the oil changed. Now I do it myself. It is so much cheaper and I don't trust people. Especially the quick lube places that like to spray paint the oil pan for some stupid reason. I use Castrol GTX 5w30 in my Cobalt with Mobil 1 oil filtres. In the diesel I had, I used what ever was the cheapest. And then I also don't get the places trying to upselling me stuff I don't really need.