Quote Originally Posted by 2wheelsforme View Post
Octane is a measurement of the gasolines resistance to knock or ping also known as pre-ignition. It is not better or higher quality fuel. If your engine does not knock or ping with 87 then you are wasting money running a more expensive higher octane fuel. Nor will using a high octane gas give your bike better mileage. That's because the rating refers to how much energy it takes to ignite the gas, (slower ignition equals less pre-ignition) not directly to how much energy the gas puts out.
Have to disagree here. I use mostly 87 and get the standard 40-42. We have a place here that still sells "91 ethanol free", when I use that I get 43-45 mpg. I believe it also runs a little smoother on take offs. During this years rally, when we were in CO, we were getting 50 on some runs, but drop some elevation and get into Kansas, the mpg's dropped into the 30's