Originally Posted By: FrankN4
If I may ask a question based upon my lack of education on the subject. Would not a motor oil with a high quality GP III base, a healthy(whatever that means) dose of a high cSt PAO as an additive, have the potential(if the add pack were tops) to be an extremely high quality oil?
Sure. Group IIIs vary in quality, but the best of them rival PAOs in most respects except low temperature flow. The low temperature properties can be improved by adding some low viscosity PAO or ester.
High viscosity PAOs are generally used in small doses (single digit %) as a shear stable thickener and are claimed to have some anti-wear benefit as well. A robust DI package (additives) is most important overall for a high quality oil, and synthetic base oils become important for extended drains or hot operations.
While my driving really doesn't require it, I use M1 EP because I like their combination of Grp III+, PAO, AN, POE, and high visc PAO with a robust long drain additive system. I run 10-12k OCIs.
Tom NJ