Bobistheoilguy.com is a good website where people discuss engine oils and their additives. Zinc is a big one, but I’ve also seen talk of boron and calcium...as I recall, they’re all on the periodic table in the same family or closely related. Also, the RVS treatments some of us have tried/use are borosilicate, and I can attest to them making my engine and transmission work better, Post-groove, so there’s something to it...