I purchased cases of Mobil 1 and since Mobil has come out with so many different kinds of applications for their oil, I called Mobil 1 Ask hot line and asked it Mobil 1 High Mileage is Group IV P.A.O. and was told he couldn't answer that. When I called QuakerState oil company, they responded immediately that it was Group III. Nothing to hide. What's with Mobil? It's called product information but, won't tell what it is. I'm wondering if they are starting to use Group III in some of their oils. Moisture doesn't seem to effect P.A.O. as does petroleum oil. It's important to be because of use application. Appreciate any help.