Higher Octane rating increases self-ignition temperature and thus reduces knock/detonation, but it won't affect flame speed (once spark ignites fuel mixture) enough to matter. Below is a summary that basically says the same as my old Internal Combustion Engines textbook.
Keep in mind that motorhome and generator engines operate at relatively slow RPMs compared to racing engines, so fuel mixture flame speed is likely even less important.
Whitfield Oil Company Flame Speed, Octane Number & Horsepower
OCTANE NUMBER:
The octane number of a gasoline has little to do with how fast it burns or how much power the engine will make. Octane number is the resistance to detonation. If the octane number is high enough to prevent detonation, there is no need to use a higher octane gasoline since the engine will not make any additional power. Octane number is not related to flame (burn) speed either. Variations in octane quality are independent of flame speed. There are some high octane gasolines in the marketplace with fast flame speeds and some with slow flame speeds. It depends on how they are put together. We prefer fast flame speeds because we know that a properly tuned engine will make more power on this type of gasoline than one that has a slower flame speed.
Thor Forums
