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Ethanol Marine Problems

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Read up on the fuel additives for E10 problems. The MDS sheets list mineral spirits, alcohols, and petrol distillates either separately or in some combination. The advertising claims “removes water, detergent action, and protects wear surfaces”.


Instead of these additives, better to use Marvel Mystery oil and regular E10 fuel already with ethanol. The logic of fending off problems of E10 by adding alcohol escapes me? Marvel Mystery oil probably good for most engines, as the oil probably contains high pressure additive sulfur and maybe a little chlorine. Not to good for air pollution, but mechanical parts will glide easier.


Consuming public seems baffled by the hype of ethanol damage. They are getting manipulated into sales of costly additives and mechanic repairs. It appears to be a cash cow for marine industry.


Now, I will dummy up that ethanol is hygroscopic. That the fuel will attract water from atmosphere. But, most don’t realize diesel fuel also hygroscopic. But diesel fuel is not miscible with water. Water just sets at bottom of tank, alone. Ethanol is miscible with water and will form a solution with water and is able to burn this solution up to 50% water mix.


Does chemical bonded water stall engines, rust out fuel lines, or reduce fuel octane? No. In fact molecules of water within chemical bond of ethanol raise the octane rating and what I read the hydrous ethanol isn’t corrosive. At least with within ethanol produced by modern ethanol plants, which readily test quality of fuel. The days of old, when gasahol was quickly introduced upon the nations fuel supplies without much regard to quality control...gone. One problem back then was accidental contamination with chloride. Maybe from city water supply? Chlorides will foster stress corrosion, but modern plants keep the standard to 1 ppm or less within fuel tank. Also, if the fuel is slightly alkaline, another deterrent to corrosion.   


Will water content within ethanol decrease engine power? Yes, at WOT, but at lower hp demands it will just require more fuel/water mix. But, again were talking of ethanol with something like 25% water. Meaning E10 with H2% water. And don’t forget ethanol is doing you a favor by pulling water out of fuel tank. What would happen if like gasoline, per usual, allowed water to accumulate for resulting stalled engine at sea? This would be pure water into high revving engine with zero lubrication.  Ouch!


Will water content within ethanol stall engine? Probably not unless your past 25% to 50% water content. It will not be top quality fuel, as starting and idling will be not as smooth. Two cycle engines would have a slightly diluted oil mix because of water, not a good condition, but better than running pure water through the high revving via the old water gasoline problems.


Most boats do not have fiberglass fuel tanks. Those old ChrisCrafts and old sail boats aside. Most of these have long ago been updated as fiberglass was a horrible tank material even with gasoline.


Venting fuel tanks to air not a good condition for water accumulation. Florida, New Orleans, Houston, etc. being extremely humid would also normally experience extremely vicious cycle of water problems with all fuels. Best advice…..keep the tank filled and while boat is in dock place plastic seal on your air vent. Be sure to burn some fuel and refuel every few weeks. If worried dump more ethanol in tank with Marvel Mystery oil.


Ethanol as an additive for marine fuel. It would be a good test…..to compare E5, E10, E15, and E25 fuels for marine use. I suspect the more ethanol the fewer problems. Ethanol or not if you have a history of water problems in fuel, good to keep the tank full and seal the tank from ambient air during docking.


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An article I read in one of the boating publications suggested that around 1% of the boats out there would have problems with E10. I think most of the noise surrounding this issue is just marketing to sell additives and expensive E0 at the marinas.

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