I've been running ethanol fuels since ethanol was mandated. I've probably got 25,000 to 30,000 miles on sleds running ethanol and have never had an ethanol related problem. I have experimented with straight 91 octane gas when available and have never seen a performance gain that was noticeable running 91 non-eth versus 91 eth. I may be one of the few retards that has run his sled in non-eth mode with eth. in the tank. That combination actually makes for a noticeable performance improvement at 8,000 to 11,000', and have never had an issue or failure running in that non-recommended setting. Some high volume high performance oriented dealers actually recommend running the Polaris Axys with an aftermarket single pipe on ethanol in the premium setting without a fuel controller and pretty much guarantee you won't have any lean burndowns or any other issues at elevation. It appears they are now mapping so rich that even retards can't burn one down, I guess they call that making a product "Consumer Safe".