Originally Posted by MMZ_TimeLord
Not bad as a serious octain booster... you could add the five gallons to a nearly empty tank, then top off with 91 or better and get nearly 100 flat for your average.
I would never do this except at the track myself...
Do you believe it would have a negative effect on any emission controls or parts? My thought is exactly what you stated and do a mix just for track day.
Steve