When you "peel back" all the marketing regarding Castrol EDGE and Magnatec - it collectively has dawned on me from recent posts by Gokhan and others that spec for spec the Castrol - USA synthetic oils just don't match up as well to SOPUS , Valvoline and possibly M1 synthetic oils ? From lack of GTL base stocks (or equivalent ) to VII % , NOACK , temp ratings and other key specs. what Castrol ships to the USA is essentially a Tier 2 / Tier 2.5 synthetic oil . True , both EDGE and Magnatec meet D1 / Gen 2 and Magnatec has posted good UOA wear numbers - but for what you are getting for your $$ the SOPUS , Valvoline and possibly M1 oils appear to be better $$ spent . *Those smarter than me with factual data please feel free to weigh in on one side or the other ...