Anybody at elevation running 88 octane in AC HO engine?

[Escmanaze]

So I just bought a 2011 M8. The gas cap clearly states it wants 91 octane. However, I live at 4500 feet, and most of my rides don't start until I'm at least at 7,000 feet. So...can I get away with an 88 octane instead?

The reason I ask is because I'm a guy who tends to believe in the whole "ethanol is the devil" thing and ethanol free gas is fairly easy to find in 88, but quite difficult to find in 91. So I think I'm doing my engine a favor by not putting ethanol in it, and I think that with the elevation difference, it won't have premature detonation with 88. I hope. Anybody have any experience with this concept?

The perfect solution obviously would be to buy some C10 from VP and put in 1 gallon of that for every 3 gallons of ethanol free 88. That's just a lot more work for me to be buying 5 gallon drums of C10 every week from the station that is 40 miles from my house. Not to mention the C10 is pretty darn expensive, but that I can live with if I could just buy it more conveniently.

Or I could just give up and buy 91 with ethanol from wherever.

 

[Bowfisher]

I run 89 non ethanol in mine and haven't had any issues. I too live around 4500' and most my riding starts around 6500'. I would like to know what exactly the increase in elevation does to octane requirements. Can you drop one octane point for every 3000', or what exactly?

 

[m8braaaap]

I ride anywhere from 9000-13000 and run 87 octane in my 2012 m8.they say 91 octane is for low elevation.dont know the real facts or details though

 

[Bowtie496]

I was told by dealer that I could run 88 at the altitudes I ride (6000-10,000) in my 14. I never tried it in my 11 because I have a source for ethanol free 91. There is a station near me that now has ethanol free 88. I may experiment this year and see if there is any noticeable difference. In theory, lower octane should have more power, until its low enough that it starts to det.

 

[CANNONMAN]

Most of the riding on the Mesa is at 9-11,000 and all I run is 87. No problems at all. I have run it in my last 4 sleds, '13 800, '12 800, '09 M1000, and my '05 M7 had 6600 miles and never torn down. I have guys all the time request 91 but it is just a waste of money. Stocks sleds can't utilize 91 at higher elevations.

 

[Escmanaze]

throttle

Good to hear some of you guys have had success with it. I might just give it a whirl and see how it goes.

My other justification is that the only thing I will really ever be doing at 4500 feet will be pulling it on and off the trailer, so I will be going pretty easy on the throttle as well at my lowest elevation. My understanding, and somebody correct me if I'm wrong, but the low throttle area seems to be the least prone to premature detonation, so that's one more thing working in my favor hopefully.

 

[hansenmac]

87 octane at 1700 feet.

live in ND and ride at 1700ft, and I have run 87 octane from the farm tank and never had the warning light come on. maybe if you ran it hard but its flat here so no long hill climbs to heat up the head. the sled was a 2010 m8 by the way.