[SCOBRAC]

It would make slightly more power, but for the cost you wouldn't see a great improvement. Where octane makes a difference is when you run so close to the maximum operational limits of a machine, not running it would do damage. Examples are in an airplane that needs to extract the greatest possible power from the smallest lightest possible package.

Cars are (were) like this to a point. Maximum performance meant maximum compression or the ability to compress as much air / fuel into a single space. That typically meant taking 12, 13 or even 14 times the volume of a space, in this case an engine cylinder and compressing it into the combustion chamber... e.g. 12:1 13:1 14:1 compression. Doing this creates extreme stress and friction, and heat. This heat and the rate or amount or timing (how you fire the mixture) caused things like pre-ignition, a condition in which fuel mixture ignited before the spark sets it off or detonation a condition where the mixture fired at an the wrong time or continued to ignite after the spark plug fired.

High octane fuel does two things. It has more energy available to harness the increased compression as well as ingredients and inhibitors which cause the fuel to be more stable at higher flash points and decrease pre-ignition and detonation. Modern electronics and engine management do this for you to a point making "high octane" fuel less of a requirement for a modern car. Even high performance cars will retard the timing automatically if detonation (pinging) is detected without you knowing it is happening.

If you want to try 100 octane fuel go get a gallon of Xylene from Home Depot. It will be in the paint department. Put it in your car when you have about 5 gallons of 92-93 octane gasoline. 5 gallons of gas and a gallon of Xylene is a blend yielding 97 octane. 6 gallons of 93 and 2 gallons of Xylene yields you 98 octane.

Xylene is 114 octane by itself but it's use should be limited. Concentrations over 20% will shorten the lives of your rubber gas lines, carb seals etc.