What should I fill my bike with?

[Carter Turk]

I haven't worried about ethanol free in my wife's stock 1150 engine, but I did try to use ethanol free in the Kat when I had a big bore kit installed before blowing it up in 2018. I did have 15 + years trouble free with big bore installed, even a 5500 mile ride round trip to Michigan, but problems arose from the starter clutch exploding multiple times.

I can say that I experienced 10 mpg less with 10% ethanol on 400 mile round trip.

The beater 2004 750 track bike I acquired, apparently was mapped for 50/50 92 octane/110 race fuel @ $70 per 5 gallons or pure race fuel.
I honored the mapping for 2 years riding the bike @ only trackdays & in those instances a performance gain is definitely felt thru the leathers.
Don't think it's really worth the expense monetarily, especially on the street, but it sure is apparent when twisting the throttle.

[Cyco-Dude]

There is a lot of discussion about gas with ethanol. In my area, there is no option, it all has up to 10% ethanol. I have never noticed any problems. I treat it before storing for the winter, but that is the only time I do anything special.

There are a couple; the closest would be in Kettering: marathon gas @ 1890 E Stroop Rd sells 91 octane ethanol free, but it is very expensive. I only use it if I don't plan on riding any time soon. Casey's general stores sell ethanol free as well, but they would be a bit further away for you.

Otherwise, manual for my GS calls for 89 octane.

[wymple]

Around here, all Casey's have is 87 octane, one ethanol, one ethanol free. Ethanol is supposed to be worth 2 points of octane rating, and my experience says yes.