i get a few questions like these, and i just want to clear a few things up. il be as informative as i know.
octane, as i said before, is the resistance to ignite. so this means the higher the octane the later in the piston's cycle it will ignite...so more compression is possible, and this means better performance, and power produced.
so for an engine, perhaps lower octane is more practical, but if you want anymore power without breaking the bank, higher octane will have to do.