An oldtimer confided to me (after a few drinks) that oil refined from Pennsylvania grade crude has an inherent natural ability to resist oxidation and a robust viscosity index. He went on to mention that these characteristics make for a better Motor oil. I am inclined to believe that the modern additives negate the need for PA grade crude oil. However, if Pennsylvania grade crude is best, which oils have it? Do Quaker State and Pennzoil include it as their name implies? I suspect that this may be an urban myth with some truth to it many many years ago.