The man next door to me is retired but sometimes works at the marina here. He said that the mechanics there tell everyone to use the higher octane. When in NH , a friend worked part time for the state. he said that every night they drained all of the fuel from the equipment , otherwise it would separate by morning & ruin the engines!
Irish
P.S. By equipment , I mean mowers & any small lawn type things. (trimmers , etc)