Can anyone provide any analysis records vs the two? I drive a 04 duramax that has alot of performance modifications and all those guys use amsoil and I find amsoil overpriced and just popular. We use schaeffers in all our equipment. Engine oil, grease, hydro oil, atf, differential etc all schaeffers and have had tremendous results with it but I would like to see some comparison. Thanks BTW What do you guys run for oil in your heavy equipment and diesel pickups.