OVERKILL
$100 Site Donor 2021
Amusing that this product doesn't really have much moly, according to the couple of VOA's done on here years ago:I run a 5qt jug of Quaker State High Mileage 10w40 syn blend with a bottle of Schaeffer Moly EP in my 93 C1500 5.7l and it is great. Probably equals a 50 to low 60 weight, did the math once, think is was 15-16ish cst at 100c. but can't remember exactly. Have ran it for a while but will be switching to QSFS 5w40, Walmart sale, w the Moly EP for a while as I bought a bunch of it. I was running 5w30 but was burning oil, now consumption is way down. Once my stash of 5w40 is gone I will go back to the QS HM blend, great oil for the price. Last summer I ran 5w40 Rotella t6 and it was fine too. Run any 5w40/10w40 synthetic or blend and you'll be fine. Mobil has the 10w50 and Castrol GTX HM has a 20w50 which will work too esp if hauling or towing w it.
https://bobistheoilguy.com/forums/threads/schaeffers-moly-ep-oil-treatment.122453/
https://bobistheoilguy.com/forums/threads/schaeffers-moly-e-p-oil-treatment.35755/
100C Visc is 238.5cSt, the QS HM is 15.9cSt @ 100C. The Shaeffer bottle is 0.473L so added to the 5 quart bottle, would constitute 7.68%. Using Widman's visc calc, that gives us a blended viscosity of 18.69cSt, so about the middle of the xW-50 range, probably effectively a 15W-50 or 20W-50.