Ran into this in Nebraska (or Utah) week or two back. Maybe I'm blessed where I live, I can fill up w/ non-ethanol fuel everyday. Out west the past few weeks, the bike ran like total **** on occasion due to the ethanol based fuels. Loud, clattery valves etc....was not used to that much noise from the engine.

So 88 or 91? which would you choose?

 

Octane matters. 91 w/ ethanol. It reduces fuel economy by about 2-3%, but it's still better than 87 or 88 octane for our bikes. Most Shell and BP stations in Nebraska have ethanol-free 91 octane. In Iowa, you have a choice between 87 octane WITH ethanol, or 87 WITHOUT ethanol. LOL.

 

I'll take the non anytime I can find it.

 

Because of the compression on these bikes I would at lower altitude run the 91, up at higher altitudes you might get away with the 88 but I wouldn't.

 

I always run the highest octane available and haven't had any problems

 

 

 

Have done well with 90 Octane Ethanol Free , which is the closest available for my area, not sure if would want to go any lower, but never had any problems with the 90 Free ...

 

I run 10:1 pistons and need the Octane, luckily as Uncle G noted, upstate NY has several brands of Gasoline running Hi-Octane Ethanol free Gas.

 

91 every time...no matter what...