ive used both in multiple applications ( bike, snowmachine, mower, cars ) and have never seen or felt a difference. which leaves me to ponder, is there really such a thing as higher octane or is that 94 octane really 87 that your pumping in your tank? now i know what some will say, i say is it really beyond the fuel companies to pull something this bad and rip us off? just a question take it as a joke or just food for thought

 

hey im working on not being a hang around what can i say only 4 more to go woo hoo

 

If your engine does not ping or knock when you use the lower octane, then go ahead and save yourself $15 a year.
Air cooled engines have a hard enough time getting rid of all the heat that they need to to keep from melting down. When an engine knocks you get all heat and no power. It's easy to hear a car when it's knocking but a Harley has so many noises it would be hard to pick a ping out of the cacophony (been waiting years to use that word)
Besides, doesn't it say in the manual that failing to do so amy cause serious injury or death?

 

I run the highest grade I can find (92 around here)...

 

I've only used 92. Almost had to settle for less when the pumps I stopped at were out. But found another station open around the corner with 92.

I think anything lower would still work to get you by in a pinch. May suffer some in town milage with it being lower, as for being on the open road it prolly won't bother a thing.

 

Avgas is 100LL or 100 octane with a minimum of lead to maintain the octane. It is used mostly in air cooled engines which operate at head temperatures of 350-425 degrees. It is much more expensive, about $3.65 around here. The only plus would be fast starts, and the one negative would be lead deposits on valves and piston heads. Lead sort of helps lubricate valve stems too but in today's engines I doubt that adds much to anything. Just MHO>