I didnt realize this but API is trying to phase out wear metals in engine oil. The currnet SF spec has it down to 1/3 of what it was 15 years ago. I used to make oil for Amalie and now it doenst matter what brand you chose, Mobil, Exxon, by law they all have to limit the Zinc dithio phos. For $10 a crankcase this might be worth adding below. it triples the levels of Zn and P. Of course it causes cancer in lab rat though...
2 ZDDP MAXX ENGINE OIL ZDDP ADDITIVE ZINC & PHOSPHORUS | eBay
2 ZDDP MAXX ENGINE OIL ZDDP ADDITIVE ZINC & PHOSPHORUS | eBay