First time on site and was looking for some help concerning Schaeffer Oil verses AMSOIL. I have a 2004 GMC 8.1 Liter Big Block V8 with Allision 5 spd and pull an 18k 5th wheel.
I know both oil's are of the best quality but the Schaeffer product is about 1/4 of the price for the motor oil.
My...
