Thanks - so the manufacture detunes the engine in ethanol mode....I assume they are assuming gas with ethanol in it and it possibly sitting is going to happen so erroring on the side of caution.   I have found my 900 can range a fair amount on gas consumption based on how you ride it ....  

Ethanol in fuel, makes it less "fuel efficient", thus requiring more fuel in the fuel curve. detonation is only part of the issue. Look up fuel mapping for the e85 tuner car crowd, if you want a rabbit hole to go down. It is crazy.  Ski

They have the option of switching between fuel settings on the 7S display, the 650 was designed to be able to run on 87 but obviously will run on either. When in doubt running in ethanol mode is safer but u do lose a touch of the performance but not much. The 650’s we’ve owned have consistently been amazing on fuel rivalling the 900 Ace on range. 

Why is there a non ethanol mode to select? to me that tells me the sleds parameters are set for a gasoline with potentially less octane since ethanol increases octane. so you should have no issues running it in that mode and with fresh ethanol fuel since it’s potentially a higher octane fuel being used reducing possible engine knock, but any modern engine will detect knock and take away timing to compensate for possible crappy gas.    interesting to hear from anyone with greater knowledge on the poos (@Nunz ) and the rationale used for this setting/design. 

That's why better than I could find last year.