Are any of you using Rotella T 4 15w 40
Been reading about it for a while and all looks good. Just like to hear from actual users.
I like the zink and all for these old engines.
Thank you

 

I have used Rotella 15-40 over the years and their formulations have changed over the years also. Then and today my reason would be a non-synthetic oil suitable for Flat Tappet (lifters) Engines and they kept the desired zinc and other additives to prevent lifter bottom/cam wear. These additives removed from Auto/Gas engines because of ruining Catalytic Converter's. ZDDP is the needed additive. There oil producers, not everyday name brands that have these oils. One link below, others to see and maybe you have looked at all. Cap

https://motormouthradio.com/blog/392-diesel-oil-flat-tappets-gas-engines