Fail.amsoil > royal purple //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif
All a matter of opinion. RP has had some shearing issues in the 5w 30 with high HP applications. You cant make a blanket statement like that anyway there are like 4 different levels of Amsoil. Any of them will be more protection than the average car needs. Its a waste in most applications over Mobil 1 or Pennzoil Platinum. for an extra 2-3 dollars a quart.Fail.
Amsoil makes great remote filteration kits, and double filter kits, and things of that nature. Their oil is good as well, but not better than RP. Rp and Redline make some of the best fluids that you can get on the retail market.