i've been using amsoil...i like it alot but the availability isnt as easy as the local auto parts, for me. I've seen the "Purple" at napa auto parts and thought about it..i've read it is really good stuff too......my guess all synthetics (that are motorcycle compatible) are better than ol' dino oil.capt42a said:LOL !!! I've been using Mobil MX4T, and am considering going to the Royal Purple due to the coat difference and availability, Mobil MX4T ($7.00 qt ) Royal Purple 10W40 ($5.99 qt). I'm just trying to see if other people have tried Royal Purple, and their opinions of it.