I have run Amsoil many times in my vehicles since 2009. That's when I became a preferred Amsoil customer. It's good stuff. Here's a thread I did when I ran it in my Denali not long ago:
https://www.tahoeyukonforum.com/thr...w183k-miles-amsoil-0w-20-w-8-5k-miles.139128/
I'm currently running Amsoil (10 gals) in the 12.7L Detroit that's in our Prevost bus/mh.
I run Amsoil atf, gear oil, and grease in my vehicles too.
If I were to describe any 1 oil brand as "THE BEST" it would be HPL by:
https://www.hplubricants.com/about-us/
Customer Service beyond compare. After talking to you, they'll custom blend you whatever is decided. They have on the shelf products too. Of course you don't get something for nothing.