Can you use 100 octane airplane fuel in your motorcycles or cars?

You sure can. Octane is just an anti-knock rating. Higher compression engines require high Octane fuel to keep from knocking or pinging. This is perfect for high performance engines such as race cars and motorcycles. However in your daily driver it will not do anything but put a strain on your wallet. High Octane does not create more horse power but rather lets you tune your vehicle for more power output by being able to up the compression ratio. So to answer the question, can you use it? Yes. It just won't do anything.