The Rotax engine is designed to run in auto gas and I think 91 octane is the recommended octane. I live in Colorado, well above sea level. I normally put regular in my tank so I don’t remember the octane rating of “premium”, but I think it is 89 out here, and regular is 85 if I recall correctly. It also contains ethanol. What do all of you Rotax owners(who are well above sea level) use in your Rotax engines?

Steve