Ethanol

[David Pyle]

Does it harm aircraft engines?

[steen]

I don't think ethanol would harm the engine per se, but what it might do attacking fuel bladders, fuel lines, carb floats/seals and
Bendix fuel injector pump seals/lines/flow dividers could be bad, very bad. I'm sure someone is testing for answers and until we know,
I intend to avoid it, even in my plane with autogas approval (not a Comanche).
Steen

[JIMICS2452]

Ethanol alone will not harm our engines, but as has been mentioned it can/does attack all the bladders, seals, diaphrams etc in the fuel system. Ethanol is also a great attaracter of water, which it will hold in suspension in the fuel. Over time the water will corrode the metal parts of our fuel systems and render them junk. This is a common occurance in boat engines and in the small engines used in lawn mowers, weed eaters, and generators that are not used on a very regular schedule.
Jim Hiatt

[David Pyle]

For the same reasons discussed here it is damaging to older cars. I have a 1958 MGA and have been advised to try to find gas without ethanol, or use a "stabilizer" additive. It is surprising the damage done in the relatively short time since ethanol. Seems to be more prevalent with infrequent use vehicles.

I assume no ethanol in avgas...