Dang, there are SOOO many more downsides to ethanol than these, and they are bigger.
I'll add that with Ethanol you may not know what your octane rating is. Ethanol, like all alcohols, absorbs water. When it does, it affects the octane level, and not in a good way.
Then there is the fact that Ethanol doesn't have the same energy density as raw gasoline. This means you will have slightly less performance and range than with gasoline without Ethanol.
Some pilots also have fiberglass fuel tanks (not the slight of course). The Ethanol does, over time, eat epoxy. Coated tanks aren't immune, but a good coat of Jeffco Sealant does mitigate this to a large degree. Epoxy structural adhesives aren't immune, though. Did I say "structural"??!!
The problems most commonly referred to are the problems with rubber and shelf-life. Some pilots "get away" with using Ethanol because they fly often, which changes up the fuel often, and don't have a lot of rubber or other susceptible materials (fuel lines, gaskets, o-rings, etc.) -or- there's a looming problem that aren't "yet" aware of. We get lulled into thinking it's OK when there isn't an immediate correlation. The effects of Ethanol on a plane can come "later".
But this ignores the other, bigger issues I mentioned at the top.
Just say NO to Ethanol and your plane and engine will run better and last longer!! It's not worth the slight savings.
Find airports that sell unleaded fuel (MOGAS, UL94, and soon G100UL) at
flyunleaded.com