Well if I use Honda vtec as test engine, then there would be "zero" benefits. And after that used for emission regulations by using lower octane fuel and different timing for it. "Anti knock sensor" equipped cars can benefit higher octane, if it's tuned from factory with bigger compromises on RPM range, i.e. Honda vtec has less compromises and practically zero benefits from higher octane.. But I won't continue to share this more, waste of time and reminds too much of school, instead now I might understand teacher point of view when he tried to sharpen blunt knifes of classroom.