I youse RP in all my cars, I know alot of people are amsoil fans, and i am sure it is a very good oil but i have never had performance gains from anyother oil except RP. I was lazy about switching oer to RP in my truck, the dealer gave me free oil changes for the first year. and when i did my first oil changed i finaly switched over to RP. and i could notice a slight "seat of the pants" performance gain but what i also noticed is my truck will stay in MDS much longer andit will evan climb slight hills on the highway with it still in MDS. wich intern got about a 3 mpg gain. with no diffrence in driving habbits. I use RP in everything. well almost if i am getting free oil changes of course i will wait. as you know oil isn't 89 cents a quart anymore