Originally Posted By: LS2JSTS
Some one on here told me a simple test.
Just add a few drops of water to a small amount of fuel. Shake it up, and if the water seperates out then it's pure gas. If the water gets absorbed by the fuel then it likely has some percentage of Alcohol(Ethanol) in it.
Or use a drop or two of water-based food coloring. If the drop settles to the bottom without mixing, you've got real gas; if the food coloring changes the hue of the fuel, ethanol.
Always take proper precautions when handling gasoline.