Hmmmm, I agree with both of you. It seems to have a friction modifier-type additive in it, which we all know is a no-no, but Royal Purple says it is compatible with a wet-clutch system. Hmmmmmm...I'll just stick to my Amsoil which contains no friction modifiers and is a buck or so cheaper per quart! If you ask 10 people about 10 oils, you will get 10 different answers, but I think we all agree that lubrication is a top priority. Concerning the Royal Purple, see page 13 of the Amsoil white paper (link above) for the details, or just read the following concerning the metal wear test:
"Interestingly, the SAE 40 oils with the highest and lowest levels of zinc, Maxima Maxum 4 at 2,464 ppm and Lucas High
Performance Motorcycle at 860 ppm, had similar mid-range results. Royal Purple, with an average level of zinc (1,474 ppm)
had the largest wear scar (nearly 55% larger than the next closest wear scar size). Zinc levels for those oils performing the
best, AMSOIL MCF, Mobil 1 MX4T, Motul 300V Sport and Torco T-4SR ranged from 1,061 to 1,762 ppm.
The SAE 50 group showed a similar trend. Golden Spectro 4, with the highest zinc level (2,162 ppm), performed less than
average in the 4-Ball Wear Test, while the Motul 300 V Competition, with one of the lowest zinc levels (1,048 ppm), tied with
AMSOIL MCV and Torco T-4SR with the best test results."
Like I said, everyone likes their thing, and everyones oil is better than everyone elses. Best to be informed and make your own decisions as to what you want to put in your 10,000 rpm $5000+ motor that was not designed to go fast and turn left