well i saw a post at the S2ki forum and someone did tests with about 8 different oils. Brands inlcuded as i remember was like mobil 1, castrol, amsoil, quaker state, and a few others which i can not remember. I am going to search for it and see if i can post it. They did all these really technical tests with all these fancy words that i would not even understand. Anyhow i think mobil 1 came third place. Castrol came second and AMSOIL came 1st by far in almost every category.