yes oil makes a difference - in an engine setup for it in the first place
is your engine stock or built? forced induction or not?
broad sweeping statements like "royal purple sheers too easily" is really inaccurate. Like everything else out there, Royal Purple, Amsoil, etc. have various blends. There is not 1 oil. The latest trend of the day is high fiving every oil that has tons of zinc....as if it's a cure all. Everything has a positive and negative to it, zinc included. And in some applications, uses, low zinc is necessary, not high zinc. As such, each brand have different formulations for different applications. When considering using these higher end race grade oils., consult your engine builder