E10 and E0 pump gas power difference?

[Truckedup]

Right now there an ongoing street bike discussion about E10 pump gas...The usual stories about ruined engines and so on...I'm not interested in those stories but is there an actual difference in power between E10 and non ethanol pump gas using fixed jetting on a dyno or race track..
I know the difference in BTU's is about 4 percent, one main jet size more or less......On my well tuned Ducati 900cc street bike with carburetors, I can feel no performance difference between non ethanol 90 octane and 91 E10...The bike is jetted for best power and ridability on 90 octane non ethanol..
Are there any reliable dyno results on the two fuels?

[Frankshaft]

I am with you, I don't think there is any power if its tuned for it. My one carbed snowmobile runs much better on E10 91, vs 91 non oxy. Only because its jetted to rich. So, when its on ethanol fuel, it is closer to the proper jetting. When its on non oxy, its way to rich. But I think once dialed for each fuel, there is no difference.

[steve316]

On a pump gas 427 sbc E10 made 7 hp more than the non ethanol gas. I did't see that coming; as was just checking for mixture jetting difference.

[Truckedup]

I am with you, I don't think there is any power if its tuned for it. My one carbed snowmobile runs much better on E10 91, vs 91 non oxy. Only because its jetted to rich. So, when its on ethanol fuel, it is closer to the proper jetting. When its on non oxy, its way to rich. But I think once dialed for each fuel, there is no difference.

But is the difference between the fuels so small that on a mildly tuned engine there would be no difference in power with the same jets?

[Brian P]

Despite the angst expressed in some internet forums, with one exception I've never noticed any difference in how any vehicle runs on Shell V-power 91 (common non-ethanol gasoline available here) or on anything else. The one exception is my ZX10R which has Wossner 13.5:1 pistons ... that bike is not happy on anything short of 93 octane, all of which is E10 in this area. (I normally use PetroCanada 94 and that's what it was tuned on)

I do use Shell 91 in the small engines that see infrequent use and in anything carbureted, but not because of power difference.

[barrybasinger]

In theory, one would run a little richer AFR with ethanol, and could run a little more advance--which may or may not help. But it seems to me that any actual difference would likely be small enough that it could easily be hidden in dyno variations. Especially for the typical street bike. That'd make it hard to prove either way using a dyno.

[Wiz_kid53]

I don't have any dyno data but there is definitely a seat of the pants difference in the lower rpm range and in throttle response from pump gas to rec fuel (no ethanol) and you can store your bike without stabilizer and it will fire right up and not run differently. I have noticed a little earlier roll over for the power curve on the top compared to pump gas, possibly because of the 4 octane difference.