I very seldom run anything with ethanol in it for many reasons, some philosophical and some real. Citgo here in WI has high octane without ethanol and so does the Kwik Trip chain. Kwik Trip markets it as "recreational" gasoline. (Yea, I know, deal with Chavez's Citgo or deal with the ag lobby that has pushed corn from food to gas to boost prices, I really don't know which is the worst)

 

EtOH hurts your mileage because your engine is not optimized to burn alcohol. Because of the compression limits needed to prevent “engine knock”, a typical gasoline engine can only deliver about 25% efficiency — only 25% of the BTU's in a gallon of gasoline are converted to mechanical energy that turns the wheels of the bike, the other 75% is lost in waste heat. An Alcohol Engine can deliver about 40% efficiency — 40% of the BTU's in a gallon of ethanol powering an Alcohol Engine will produce mechanical energy that gets you down the road.

 

Of note, the pumps you're filling up at can have up to 10% ethanol content without having to disclose it. 10% or greater the sticker has to be on the pump, though.

 

In Florida all the Shell 93 octane pumps are labled 10% ethanol. I try to use the same station locally, always the same pump and look for three hose stations when tripping. I also add Startron to my fuel. It's supposed to help with the aclohol mixing with the gasoline, gives a better burn and protects like Stabil.

 

...But there is more energy in gasoline than in ethanol. Takes more eth/gas fuel to get the same amount of energy as straight gas. That's why the MPG goes down.

 

NC, and others I’m sure, does not require labeling for ethanol. Blending is not regulated by any gov’t agency; it can be blended via an accurate ethanol/gas mixing manifold, or a "best guess" method of adding X gallons of ethanol to X gallons of gasoline already in the ground tank at the station. Either way, the resulting mixture is not routinely tested, monitored, or validated in any way to ensure the consumer is getting E10. The current blending procedures and margin for error has the potential to allow up to 20% in your E10. But how would you know? Oh yeah, carry around a test kit. My knowledge is second hand so find somebody who drives a re-fueling rig and ask them about it.

 

I have been told by my brother who is a mechanic and rides a sportster that adding some octane booster would help.

 

All I can find here is 10% Ethenol Sunoco, Shell, Hess, Lucoil and it shows in my mileage about 34 mpg combo city/highway

 

That's not true, because you're confusing BTU levels with energy efficiency. BTU levels are the amount of energy it takes to boil water, not to combust and turn a crank with the pressure. Ethanol-optimized engines can get the same or better mileage than a gasoline-optimized engine. Ethanol produces less mpg in a gasoline-optimized engine because the engine is not set up to run ethanol efficiently (not set up to take advantage of EtOH's superior combustion advantages). Ethanol (EtOH) is more efficient tha gasoline but you must change the setup of the engine to take advantage of it, just as you would have to change the alcohol engine to burn gasoline efficiently. We have gasoline engines today instead of alcohol engines because during motoring's golden years, gasoline was cheaper and also because it was illegal to possess between 1920 and 1933. Yes my background is mostly organic chemistry.

 

Not questioning your knowledge about fuels, but could you expound on the term "set up". How exactly do you modify, or set up, a gasoline engine for optimal performance on ethanol or E10?