Originally posted by Lobster
If I have a grasp on that, and the octane level makes the chain more stout, then what happens to the attached(?) octane molecules during the combustion?
The more stable hydrocarbons are reacted in a normal controlled way, they are just less likely to be be effected negatively by the temps and pressures that come into play during combusiton. So there is less of a chance of a stray hydrogen molecule teaming up with an oxygen molecule and forming radicals.