This is from the 'Royal Purple' link:
Quote:
“Anecdotal evidence based solely on the experiences of individual consumers is insufficient to support product efficacy claims, including claims related to horsepower, torque, fuel economy or engine heat,” the organization stated. “While the advertiser may quote from published articles if it provides clear and conspicuous attribution to the publisher, it may not rely on such articles to support efficacy claims for which it has no reliable independent validation.”
Seems like if that is the case, it is real hard to say that one oil is much better than another....... 
