I've been chasing a poor performance problem for awhile with my old car (1960), as it really loses power on hot (95F-100F) days in August-September and sometimes even pings or misses with wide open throttle. I'd been checking through all the usual things and narrowed it down to ignition (still using original single-points type distributor) or maybe just fuel as my compression should be just slightly higher than the 9:1 original value because during the rebuild to take out an 0.040 scratch due to a broken ring, a little skim was also taken on the cylinder head.
So, rather than go to the trouble to switch in some other ignition, I bought a bottle of octane boost, and wow, there was definitely a lot more power to be had in there and all my problems disappeared. Octane boost is ridiculously expensive, so now I wonder who is selling the highest octane gas at the pump so I can test a tank and see if that's enough, or if I need to continue to pour in a little octane boost when I want max power. I can usually find 92/93 labeled octane rating, but I wonder if anyone is selling 96 or 98?