royal purple is possibly the worst 'full' synthetic made
its not even a full synthetic...only partial
http://www.comprevac.com/products/su...ossref6_03.pdf
its flash point is absolutely terrible compare to other higher priced oils
if you drive your car hard your oil will become nearly water, trust me ive raced road courses for a couple years and used it a few times
Quote from Aaron Lail of Tru dyno spots
"I had some independant tests ran on RP, Mobile 1, and Castrol syntec.
RP was the worst and actually had microscopic metal contaminents from brand new oil! Mobile 1 and syntec came in very close to each other.
I once had a small 4cyl turbo engine running Mobile 1 that had the drain plug come out going down the road somewhere. The engine oil light came on, pulled over to check and it was completely out of oil! Put a new plug in with 4 more quarts of Mobile 1 and never had another problem. That engine is still running today! "
Redline is a good oil
But Eneos, amsoil, and motul are the best you can buy
Enoes---->the oil is polarized which adheres to metal engine components under weight transfer conditions.