I prefer straight grade over multi-grades and synthetics on the early 6s.
Right now - it's cheapest to simply add STP red bottle additive to your trusted regular oil brand.
I stocked up on last year's Rotella T SAE30 with CF rating.
By the time it's gone, I'm sure there will be other zinc additive products available.
Some major brands probably will repackage their regular oil with zinc for flat tappet engines.
With so much demand, some marketing guys will figure it out.
