I posted in the new 20k Edge thread how the tests Castrol used and percentages they exceeded them by was impressive. I did a quick google search and found this article. While the article doesn't state what oils were tested they did mention OEM approvals. The emphasis though here is the amount of real engine testing that goes into validating proof of performance. This has always been an issue for me with smaller boutique brands that just don't have the resources to do so.
Castrol
"The kind of programs I work on with Castrol EDGE tend to encompass an awful lot of engine testing," Dr Green says.
"I think most people would be surprised at how exhaustive the testing is. There's no stone left unturned in regards to which technical areas are looked at to receive these prestigious OEM approvals and the further work we conduct beyond that.
Castrol
"The kind of programs I work on with Castrol EDGE tend to encompass an awful lot of engine testing," Dr Green says.
"I think most people would be surprised at how exhaustive the testing is. There's no stone left unturned in regards to which technical areas are looked at to receive these prestigious OEM approvals and the further work we conduct beyond that.