I think you are quoting gains from RP marketing material when swiching from conventional oil to RP in the engine, tranny, and rear end (something like a 10RWHP gain). In that circumstance the gains are somewhat believeable. Just making 3 pulls on a dyno with mobil1 and then draining it and making three pulls with RP I find it hard to believe there is a consistant 6RWHP gain. Not impossible I guess - just very hard to believe.