Thread: Ethanol

I may be forced to use 91-93 octane with ethanol. Is there some action I should take, use additive, etc

No. The ethanol is Rotax approved. Won't hurt a thing. 91 oct. or higher and enjoy. Most of us use it already. Most of the Rotax engine's around the country in the US use it too.

Astark,

I assume you are flying a CT and I also assume you have the new metal fuel filter?? If not, get it done. If you aren't flying a CT, make sure your airframe is compatible with ethanol.

Hello Astark.
Fuel filter is not the unique problem.
Fuel tanks might be hurt even if they are gel-coated. I saw a CTLS with such a problem. On mine, there is not yet problems (I use unleaded SP 98 that is supposed to be free of ethanol ) but when you put your finger inside the tank, the white painting over the gel-coat is a little bit sticky in the upper part of the tank. Except with Avgas (which is more expensive and not so good for valves), in my country (France) we don't have good solution as even ethanol-free fuel contains ethanol (below 10 %, the manufacturer is not supposed to label the percentage of ethanol !) with a relative percentage that increases with time (because octane is more volatile).

Flight Design has two cautions on the use of ethanol-blended fuel:

http://documents.flightdesignusa.com...TM-CT2k-04.pdf
http://documents.flightdesignusa.com...CT__-06-en.pdf

Even though ROTAX allows up to 10% ethanol in fuel, there are other airframe components that could be affected.

Recent experience of high-time LSA owners has shown that there are apparently other problems with ethanol-blended fuel. It might be these are due to the additives included with ethanol-blended fuel in the US, or perhaps to improper or infrequent maintenance by the owners.

Has anyone experienced issues with water in the system using mogas with ethanol? Would that really be a problem if the gas sat for a long time if the plane was not flown for awhile? If flown and fueled regularly does this help eliminate the potential for water separating the ethanol from the gas in the system.
My aircraft is hangered and flown typically a few hours a week at this point. I am starting to use mogas exclusively and am wanting to understand the difference from 100LL.

Thanks,
Robert

Robert, I live in Michigan and hvve been using Mogas 100% since last fall with no problems. You can see from previous postings that a lot of CT owners are using this fuel with no concerns. It is not recommended that one let Mogas set for any extended period of time because it will pick up moisture, especially in humid environments. It is also important to purchase fuel from a gas station that monitors their fuel constantly for contaminants and that sells a lot of fuel to insure that this fuel has not set in the storage tanks. In Michigan, all of our Mogas is supposed to be a max. of 10% alcohol. I recently tested the Mogas which I buy from BP Amoco and this tested at 5% alcohol. If you are concerned about this, the testers are not expensive and you can quickly examine your fuel if you feel it has "set" too long and may have absorbed water. I think that the the fuel companies may add less alcohol to their higher octane fuels to reduce the possibility of water contamination since this fuel can be used for high performance engines. There are a few boat storage places here that sell 92 octane Mogas that has no alcohol and this fuel is best for our CT's. You may have this fuel in Virgina? Also, some airports here are looking into purchasing 92 octane non-leaded, non-alcohol fuel from their distributors for use in aircraft approved for this fuel.