Anyone use amsoil or royal purple? I know for a fact that amsoil is really really good oil and I have seen its use in many different platforms. Its only about a 1.25 more a quart than mobil 1 and it can be used for a lot longer. They say under normal conditions once a year or 25K(filter@15K) and severe conditions at once a year or 15K. Now at the price you can see the economic benefits and they have done extensive research comparing against other oils with charts on their website.
I have no experience with royal purple but have heard good reviews. So to stop rambling...anyone use either of these two?
