Sorry,

The octane refered to in organic chemistry is different than the octane refered to in gasoline.

You are right, there is an octane molecule in organic chemistry and the number of carbon atoms varies, depending upon the type of octane, but the octane refered to in gasoline has nothing to do with the organic chemistry octane.

Higher octane is achieved by adding impurities to the gas to elevate the energy required to initiate oxidation (combustion).

THE ONLY THING HIGHER OCTANE GASOLINES DO IS TO RETARD THE AUTO_IGNITION POINT OF THE FUEL.

Some manufacturers may add additional additives to their higher-end fuels and those additives may prove beneficial.

But the higher octane itself does not improve performance, mileage--anything.

Your car may appear to perform better with higher octane fuel because your engine's computer senses that it can advance the ignition timing to a much greater degree than with a lower octane fuel. So, the same car, running these two different fuels, will perform differently because the ignition timing has changed.

But the octane vaule itself offers ZERO benefit.