I used the stuff "RP" in my last truck and never had any troubles with it. Infact my dad said from start up that the truck sounded better and quiter and I could feel a differance. I just switched over this last weekend and went through the whole drive train and all and all I think RP really good stuff. I got 90% of the RP from a Fellow TDR'r, he went with AMSOIL the last minute and I bought what he had, but bought the rest from RPMoils.com and they have really good price's and free shipping... I compared the price's of the stuff that they have at Wal-Mart, Auto Zone, Napa, and Checker Auto Parts, and for what you get at RPM oils, you can't go wrong... . Hope this helps