Living in an Ethanol World - Engine & Fuel Tank Management

July 16, 2015 During the gas crisis, when the US was highly dependent on foreign fuel, the EPA mandated that a percentage of corn based ethanol was to be added to the nation's gas. What seemed like a good idea at first quickly soured in the marine industry when it was discovered that ethanol can draw water from the atmosphere and absorb condensation from the walls of fuel tanks and also acts like a solvent on plastic parts, hoses and gaskets. Additionally, it was found that ethanol's sulfate salts can corrode metals in the fuel system, fuel injectors, carburetors, intake valves, intake ports and combustion chambers. If that wasn't enough, ethanol was found to break down or suffer from phase separation over time. While those problems didn't surface immediately in automotive use (where fuel is used and refilled in a relatively short period), it became disastrous for small marine engines (dinghy engines and small outboards) which could sit for some weeks between uses. It was originally believed that the proper additives could maintain fuel for about one year. Research (and practice) indicate that untreated regular gas lasts about 28 days before separation begins and high test fuel maybe 6 months.  The truth is, if you started the season with some fuel, used the boat infrequently, then added some new fuel, there is still a good portion of old fuel in the tank. Ethanol (with 10% currently added in the US to comply with federal  EPA standards) in the fuel can draw water from the atmosphere and from condensation on the walls of the tank, and also acts like a solvent on plastic parts, hoses, bulbs and gaskets. Additionally, it’s sulfate salts can corrode metals in the fuel system, fuel injectors, carburetors, intake valves, intake ports and combustion chambers. When ethanol bonds to moisture, it separates from fuel and drops to the bottom of a tank. This is called "phase separation" and it causes two problems. First: Because ethanol boosts fuel octane by about two points, when it drops out, it leaves fuel that is below the recommended octane for your engine. This results in hard starts, poor acceleration and loss of power. Second: It can actually create a situation where your engine is forced to run on water—not good ! Additionally, the ethanol also starts eating plastic parts, gaskets and it's acids can even attack aluminum castings. So how does our engine survive in a hostile environment where salt water is trying to corrode it from the outside and the very fuel we use tries to destroy it from the inside ?  The answer is to rinse the exterior with water and flush the interior cooling passages per your engines manual.  Then you should use only fresh, high octane (high test) fuel which has been treated with fuel stabilizers (like ValvTect) and  store it for as short a time as possible. Disconnect the hose and run the engine dry to use up the residual fuel in the carburetor. Don't even think of using the gas that has been sitting for a year (or two) in your garage! Maybe you can dump small amounts of that old gas in your car's tank, where it will be consumed with a higher volume of fresh gas. During the boating season, and especially in the fall as haul out time approaches, many boaters ask our service departments “Do I fill up my fuel tanks before hauling for the winter?” The answer is two fold, yes and no !   The correct answer is you should run down almost all of your existing fuel, and THEN fill up for the Winter. If you had old milk that was turning bad, would you buy some new milk and mix them together to freshen it up?  Would you do that to your fuel ?  Ah Ha !  Using ValvTec fuel from the Cove Fuel Dock or Rex fuel station, which includes fuel stabilizers, will maintain the fuel for up to one year. For diesel, use a biocide stabilizer to prevent bacteria, fungus and algae from growing. Now, go burn some gas boating this weekend ! For more information and to see what all the marine manufacturers and the Coast Guard are saying, click... HERE See this also:  Recreational Boating Industry Turning to Biobutanol as Alternative Biofuel.   Click... HERE Capt. Rick Delfosse  

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