You or anyone you know ever tested it? it seemed there was a period where the signage stated all blends had it and then a new sign later stating 91 did not have ethenol.  if 91 has none, that should mean 87 has 10% and 89 has 5%…like shell used to state if I recall.    And btw, anyone ever frequent this area, Gibson is always cheaper then wolf….3 to 6 cents normally. 

Correct about no ethanol at Wolf and Gibson

It seems some or all manufacture are continuing to err on the side of caution with ethanol gas based on the sport and a 2-stroke being less forgiving than a 4-stroke.....a higher octane fuel is a more stable fuel reducing knock depending on compression and timing, ethanol increases octane, but if that ethanol gas sat, it become problematic of course, add colder temps to the mix, and more recipe for bad things to happen. I wonder if CAT or DOO 2-strokes have choices as well based on ethanol gas?   Whether you use 87 or 91, they both have ethanol, I think the same amount of ethanol these days too......but setting the gauge to 87 detunes the sled like you mentioned where the sled could make more power with 91, if the gas is good and at the correct level of octane to support that extra power.  I know the ethanol thing has been discussed in great deal here, like many places......I was just wondering what the manufacture mindset was with 91 non ethanol mode knowing the ethanol is used to increase the octane rating these days, and based on Nunz's response it sounds like there is an ethanol mode regardless if you run 87 or 91, that would make better sense given this day and age.....older sleds have had/use to have a switch you flipped if you ran any ethanol fuel, either 87 or 91, etc.....   Based on a search it seems even in the USA 98% of gas stations run a min of 10% ethanol, very few run with no ethanol......but I am sure @skidooboy could validate how accurate that is. We here still have gas station with no ethanol.....pretty sure every time I get gas at the Wolf station and I think the Gibson station too, there is a note stating higher octane fuel has no ethanol......  

Two modes like mentioned above on 7s display. All I know is not suppose to use 91 octane setting unless fuel has no ethanol in it. Dealer told me it has to stay on 87 setting unless you know for a fact 91 fuel is E free. There is no more 91 free fuel in my area, not able to use that mode. Ski is right it has something to do with e fuel is less energy dense too.  So far been no fix for it and USA has rec 90 fuel. Not sure if they have 91 that is e free or not anymore too. 

Here is a good deal IMO.    https://www.facebook.com/share/17gL3dCxCM/