Thanks for the corerection, Pe. I guess I was thinking of why higher octane reduces "spark knock" (pinging) in performance engines, and knew it had something to do with how the gasoline ignited and/or burned. My streetbike would hardly run on anything less than 91.
As far as the European-made engines requiring higher octane, I guess that equates to the more you pay for the engine, the more you have to pay for the gas to go in it. I should have remembered that, as I had a ZDZ.