Bought a cheap ethanol gas tester and tried it out tonight.
Pretty simple concept and thankfully reasonably cheap. Bought a Briggs and Stratton Gasohol tester, it amounts to a "calibrated" vile into which you put a certain amount of water, then fill the rest with a sample of gasoline. Total is about an ounce or a little more, not wasting too much.
Then fill with gas and shake. The water mixes with the ethanol and the separation between gas and water changes place.
You can clearly see which sample has non-ethanol and which has the more common 10 percent ethanol (almost everything in our area). If you aren't sure of the gas, and don't want to have the alcohol in your machine, here's a simple and fairly cheap way to find out before filling your tank.