High Octane is for High compression(we ain't got much). Slower burn to prevent pre-ignition. Won't hurt. And it won't help. A lot of air craft engines are air cooled. They tend to run hotter than water cooled. Typical hot spot for air cooled is the exhaust valve. It can light off the incoming air/fuel chsrge and cause pre-ignition. So high Octane for them. Slower burn and lower combustion temps might help at 12:1 but we see something like 7.5:1 so not gonna do much for us. Lower temps means less working pressure to move the piston. So less work per gallon means worse fuel mileage. Match "octane rating" to compression. Low for low compression engines( like truck and lawnmower) and high "octane rating" for high compression(like modified engines and air cooled motorcycle).

Steve H