This article talks about Pennzoil and Valvoline's so-called warranty and the battle between the two on who's came first. AMSOIL has offered their warranty guaranteeing a
1 year / 25,000 mile drain interval, since they created the first synthetic oil for automotive use in 1972. Check out AMSOIL's warranty here --> www.amsoil.com/warranty
Keeping you updated on the world of synthetic lubricants.
