I wonder why so many people dislike Castrol Syntec (U.S. Version) I have yet to see a bad UOA with it. So it's not a PAO, but is that neccasaraly bad if it is capable of doing a good job? Also I know that Penzoil is a good conventional oil (I currently am running there 5w20 for my first change), but I do have some trouble trusting a company that is willing to put their name on re-labled FRAM filters. I have to say that castrol is very stringent with there quality standards. I work at a shop that uses Bulk oil, the only way that you can get Castrol is in 55 gallon drums, or in a truck that cariies NOTHING but Castrol motor oil. Most bulk oil comes in trucks that will carry all kinds of oil's, gear lubes, ATF's, etc. All this swapping leads to contamination. If Castrol finds that you do any of this with their oil's they will cut you off as a vendor. Also their filters are re-labled wix filters. These are just some things that I have learned from working with different suppliers at our shop. Just figured I would share the info.