I think you will find lower zinc and phosphorus in Valvoline. Perhaps the ZDDP thing is like the old lead in gasoline. It was cheap so they used it, but now that lead is banned they are using other methods that (hopefully) nicely don't deposit on your exhaust valves. Same probably is true of the ZDDP. I have considered the dual rated (gas/diesel) oils, but am concerned with the higher zddp and ash contents being maybe not the best thing for my engine. But the big question is, will there be enough antiwear in the new SM oils? Will the other, more expensive compensating ingredients suffice? I guess that, since the 5w20s are showing good UOAs on some fairly rigorous use, that the same careful attention will be paid to formulating the SM oils. But if it turns out SM is not so good you can always fortify your oil with a q or 2 of Redline or HDEO.