Dynos can vary several horsepower with identical runs. A dyno has inherent variances and we can't perfectly control all the environment variables. Correction factors usually have a large (relatively speaking) ± that has to be factored into the uncertainty of the result. There would need to be dozens of runs to discern any small power increases at all & even then the operator may still have too much influence on the results. This is why the dyno charts showing one oil gained a few hp are crap and are approaching the lamest rung on the ladder of marketing. It is the precise reason why I won't purchase Royal Purple - more telemarketing junk.
