90 octane pure gas vs 93 octane with 10% ethanol

[VernDiesel]

Which do you think is better and why?
Makes more Power or better detonation resistance?
11.5-1 114ci M8

[JSD]

Ethanol is harder on rubbers etc . But octane rules . Are you pinging at 11.5 on 93 ?

[VernDiesel]

No just wondered what people thought was best and why.  I have access to both locally.

[wolf_59]

In my area we have 86 for regular and 91 for premium
I have tuned both my bikes to run on 86 one is set at 11.3 and the other is set at 10.5
I run 86 because it is available at every hole in the wall station where I have had trouble finding 91 in the past

[hrdtail78]

I'd rather tune for the 93.  I do wonder if the fuel is rated at 93 and then mixed or is it 93 calculated with mix? 

[billbuilds]

     I'm thinking that octane would have to be figured in after ethanol is added. Just found a piece that explains  some of it. I too would want to run the higher octane blend. ethanol and octane explained