I WAS running Royal purple for a few years among other oils I tested and switched to Amsoil this year. I tested additional heat treatments,coatings and various cryo treatments and have been able to extend my gear service life on bravo lower gears with some processes but the amsoil seems to have helped the lower gear life signifigantly over the royal purple so even though it's cheap and convienient for me to get I no longer run it,Smitty