Alot of people here in Alaska mix 100ll avgas 50/50 with pump premium. The best premium we can get in Ak is 90 octane. I run straight avgas in all three of our sleds since I hate mixing and blending all the time. To answer your question, it works fine. You may end up changing your jetting a little and your plug colors will be somewhat different than what you are used to seeing with the different additives in the avgas. Sure beats buying race gas, especially up here!