Originally posted by: DSengineer
Using high octane fuel on a stock compression piston will actually cause a loss of power and needlessly drain your wallet. There is such a misconception out there that dumping race fuel in your bike is going to make you go faster. It will not! Higher octane fuels burn slower than lower octane fuels in order to prevent detonation. You will make best power running the lowest octane you can just before detonation occurs. Raising octane beyond that point only creates a slower burn and thus less power.

Besides compression, cam specs as well as elevation also play a role in octane requirements. The higher you go in elevation the lower octane you can safely get away with.

With that said Fixitman69 should not be running ANY type of race gas at 5000ft elevation on stock piston 450R. Run what your owners manual says you should be running and save your race fuel money for other things.