I'm not an oil expert but I did do some of my own testing on electric air compressors after a rep from Royal Purple came by to try to sway our company away from our current oil to RP. In the end, I did not see any decrease in amps, lowering of temps, or more rpms....maybe the oil I was already using was very good.
If you think about your motor as a hydraulic pump and not a frictional device, you'll get a better understanding of how the oil works, especially on bearings. If you have any " dry surface to surface" friction on your bearings, they will be toast very quickly...the oil pump creates oil pressure to keep everything apart. Then the spinning of the components actually causes a hydrodynamic wedge (IIRC regarding the term). Like I said, I'm no oil expert, but my previous job gave me access to over a billion dollars worth of construction and over the road equipment and we could follow trends, etc. Oil failures were never a problem as long as the correct oil was used (do not put gear oil in the crankcase, etc.). Running out of oil, blowing a head gasket and contaminating the oil, etc were the failure issues regarding oil.
So if you need to polish your bearings, you'll need a rebuild before you get out of your driveway. Royal Purple may be a "good" oil, but I don't like their marketing. Regarding "designer" oils, I do like Redline as they are very up front about what oil does and what is does not do....no BS marketing, just constant and reliable products. In the Viper, I've used Mobil One since new.
Cheers,
George
