Amsoil will introduce their PAO based, CJ-4 rated, 5w-40 ("DEO") on 1 Oct, priced about the same as their 10w-40.
One of the main benefits that I see is that these CJ-4 rated oils will also be excellent for newer gas engines. Expect to see them as CJ-4/SM products for mixed fleet use.
The reduced amount of sulfated ash should have a beneficial effect on piston crown and groove deposits.
TS