I tried it out about a month ago in my 1991 Acura NSX. In controlled, back-to-back tests, the Ran Up made 5.3 wHP (2.1%) over freshly changed Red Line 5w30 by itself.
We made 3 "before" dyno pulls and 3 "after" dyno pulls, and took the 2nd best results from each group.
I just recently posted...