[Mark Henry]

If anyone wants to test their gas it's real easy and you don't need to buy a kit.

You need a small glass jar, tall and thin is best, but a baby food jar will work. A measured beaker would make the math easy.

Mark it out, you need to do the math, but you want the math to work out something like a 10%, 20% and 30% mark on the bottom and then a 100% in the middle, then a 10 and 20% mark at the top. (120%total)
Also it is best to scratch in the lines, ink/marker will wash off.

Fill with gas to the 100% line, add 10% water, the water will sink to the bottom.

Shake and let settle, if the bottom layer doubles you have 10% ethanol. If it tripled you have 20%, etc.
It works simply because ethanol mixes with water.

I've thought about removing ethanol with water, but since the ethanol effects the octane rating and I can get pure gas (premium) here easy, I've never been willing to try it.