Here is my take: To begin with, I was an AMSoil skeptic and always thought well of Mobil 1. When I read the first thread about oil viscosity drop from shear and/or fuel dilution, I started oil testing. I have done a number of oil analyses on M1, Penzoil Platinum and Amsoil 5-30. Amsoil is the only one that has stayed in the right viscosity range after 3000 + miles. On my second change of AMSoil the viscosity was at the upper end of 30 wt and the lowest wear metals I've seen yet after 4000 miles. Am now using 0W-30 SSO for winter and will get it tested when I change it at about 3500 miles.

The pdf isn't thre most beautiful, but the numbers are there. I am not an AMSoil dealer, and I will not tell you what oil to use. I will be using AMSoil from here on out.