Originally Posted by Tooslick
I've been an Amsoil dealer and mechanical engineer for thirty years and I can tell you that Royal Purple is a reputable company. Their industrial lubricants - particularly their compressor oils and gear lubricants - are highly regarded. It's certainly possibly to get good results with their engine oils in Subaru turbos if you choose the correct oil for this application. The 10w-40/HPS I cited above should work very well, given its physical and chemical properties.
I have heard the same about their oils and gear lubricants. And while there most likely a good oil made by them that can be used in our applications, there are much better alternatives like Amsoil, or much cheaper ones like Rotella. There is no need to dabble with the purple haze for these Subarus.