Before, I was not totally sure of the ill effects of ethanol in gasoline until I had to siphon it. When pure gasoline gets in your mouth, you just spit and smile. With e10... spit and frown! you can really feel the burning sensation in your mouth!!
This is what we do during my high school racing days with the "no choice" 20% alcohol.
1. Buy Alcogas (Gasohol) using containers and not direct to tank.
2. Add a little water to gas.
3. Water and alcohol mixes and settles at the bottom because it heavier than pure gasoline.
4. Siphon pure gasoline up to just above the water/alcohol mark.
5. Tadaa! Pure gasoline!