I got it off this site. The glass tube with the yellow top will tell you the percentage.
http://www.fuel-testers.com/product_gas_alcohol.html
We have the stickers that say up to 10% ethanol also. But the federal law is that all gas must have at least 10% by volume unless you buy it under a special permit.
I?m not claming my results are perfect. If there was to much water in the fuel it would make it show more ethanol. There are other things that will toss of the test. I did the test about 50 times at home playing with different gas cans before I tried testing at the pump.
The test kit is showing the amount of ?water based? product is in the gas. If a station is pumping more than 5% water or water based additives besides ethanol then they have a different problem they need to get worked out.