Mogas, Ethanol, and Water

[N404CX]

Whether Certified (STC) or Experimental, some engines can use Mogas. Does the Ethanol absorb the water so that you are less likely to see the water in the fuel tester/checker/sampler?

Any other comments on the presence of water in the Ethanol blended Mogas?

Thanks.

Glen

[Jim Heffelfinger]

Glen, ethanol is hydophilic it absorbs water up to a point and then phase separation happens. MoGas ( auto fuel) with any blend of alcohol voids out the STC. See this thread.....http://eaaforums.org/showthread.php?597-Ethanol-in-Fuel&highlight=auto+fuel
You will need to use this type of tester ......http://www.autofuelstc.com/fuel_testing.phtml
http://www.eaa.org/autofuel/autogas/test_kit.asp

You will not see the water in the drain as usual...it will be absorbed until it is "full" - phase separation once established will have the water alcohol mix on the bottom of the tank and the now very low octane fuel on the top. Detonation is a real concern. Current national blending is 10% it may or may not be noted at the pump and there are few "pure" fuel sources.
jim