>Both were E10, right?
As of either March or May 1, 2008 all grades of auto gas in Michigan is minimum E10 apparently required by the EPA. Mobil regular gas is clear E10 also. Refineries selling to each other makes it hard to distinguish brands unless maybe they are careful about who they complement with.
>where can i get this test ?
LaPointe mentioned the tester in one of his articles and I immediately went to eBay to find it. Mileage testing is easier when you don't need to play guess-the-chemical in your gasoline. Search eBay for "tester alcohol fuel". That's a small one so it requires some effort to keep it accurate but it works fine. You could do an Ethanol presence test with any test tube since any rise in the "water" level means there is some Ethanol. These tubes provide calibrated lines so you know what the percentage is by following simple instructions on the test tube. This tube measures E0 to E85.
Filling the test tube is quite easy after you've found all the ways to do it wrong. I carry around one of those high pollutin' water bottles and the water line is almost exactly a cap full. I pump gas into my tank until the shared hose is clear of the previous gas. Then I stop and withdraw the pump handle until I can tilt it upwards with it still in the filler neck then kerchunck the trigger. This fills the spout with enough fuel to pour and any that squirts out goes into the tank. By buying one gallon from each gas station you can test a bunch in short order.
Boaters don't want alcohol in tanks for any reason. You can help them find ethanol free gasoline and maybe get a few free boat rides. Airplane operators with an autogas supplemental type certificate may be buying under the assumption that E-anything would be labeled. E10 or less does not need to be labeled at the pump in Michigan. Sounds like free gas for the mechanic.
http://www.fuel-testers.com/
That's one with a bleed tool for airplanes. Any airplane mechanic should have this.
http://www.e10sucks.com/
You can see how it works and see a very accurate one up to E30 in this video.
After shaking the "gasoline" is not pure. Some ethanol and water stays in it so don't pour it into your tank for disposal. I pour it into my intake. That burns it up without polluting my tank.
>I'd love to test fuel around here.
It's already a novelty item here in Michigan thanks to our incompetent politicians. Word was that many premiums were Ethanol free but a trucker told me that as of March or May 1, 2008 no trucker can deliver any grade of gasoline less than E10. Fortunately I have found a nearby premium tank with no Ethanol so I'll be buying that until one of us runs out. If we ever get some reprieve from this Ethanol blending boondoggle I'll be able to find the first station without it.
>What is the implication of the yellow color?
Google Results for Yellowish Hue to Gasoline causing varnish and deposits
AOL Autos: Does gas go bad?
BP Advertisement for Crystal Clear Purity
That's exactly how it looks except that mine has a water line.