Quote Originally Posted by GTScoob
You want an oil that keeps its shear weight up over the entire lifespan of the oil, not Royal Purple which starts as a 5w30 and after 3K miles has a shear weight less than 20.
Any of you guys using royal purple ever send your oil out for analysis? I think if you did you would never touch the purple stuff again. That statistic is from a handful of subaru owners on nasioc as well as a handful of other car owners on Bobtheoilguy.com. I guess its good if you want to change it out every single track day (which you should do anyways) but for the long haul it breaks down very quickly.

At least Royal Purple doesnt burn multiple quarts of oil like Mobil 1 does on the majority of cars I've heard of people running it in.