Originally Posted By: 05ChevyI5
Lets say to M1 or PU? Just the old formulation with a stouter add pack? New XL all grp3 base?
Amsoil XL usually showed UOA's that rivaled any oil posted here. The new formula is the same base oil, but with a whole new stouter additive pack. I expect UOA's to be the same or better, with people going 10K OCI's. I certainly would trust it, the Pennzoil products and M1 to 10K over some of the other Group III oils raved about here.