Of the anti-wear additives that are now being used, there are zinc, moly, boron, and titanium based chemical compounds. If you can meet all SN/GF-5/4718M/dexos1, the toughest domestic U.S. specs, with ACEA A1/A5 on top of that, only using ONE (zinc) anti-wear additive, why would you bother with moly, boron, and titanium? Business case? All 5w-30s: Valvoline Synpower, Royal Purple, NAPA Full Synthetic use only zinc. 0w-30: Castrol Synteq Euro 0w-30 "German/Belgian Castrol", which passes the very tough MB 229.5 spec, using only zinc as the anti-wear additive. Kendall GT-1 uses a different approach: Put zinc, boron, moly, and titanium in there together. Castrol Edge with FST does this too. Other oils use some subset with zinc. (Fuchs is the only oil to NOT use zinc that I know of.) Is it base oil quality that negates the need to use more different kinds of antiwear additives? That wouldn't make sense, since Amsoil uses great PAO base stocks yet they use boron+moly+zinc in their SS oils.