For years, operating instructions for lawn equipment, herbicide transfer pumps, boat motors and other machines powered by small, gasoline-fueled engines recommended AGAINST the use of E-10, E-15 or E-85 gasohol. While gasohol isn’t catastrophically destructive to small engines, it has properties that can create problems.
Ethanol in gasohol eagerly absorbs water from the air. If an engine is used regularly, water absorbed in the fuel is burned with the fuel before enough water accumulates to cause problems. Any problems from gasohol come in small engines that sit unused for long periods of time. If gasohol absorbs enough moisture during those periods to the point where water separates out, it can corrode parts of the fuel system and degrade the quality of combustion.
Ethanol is also a solvent for varnishes and lacquers that can develop in gas tanks and fuel systems over time. One of the big problems with gasohol in its early years was when it was used in fuel systems that had previously used conventional gasoline. The alcohol loosened or dissolved all the gunk that had built up in the system, which then plugged filters, orifices and jets.
So. Small engines used regularly should have no problems with gasohol. According to Zach Santner, petrochemical engineer with Sunoco Fuels, the design of fuel systems in vehicles precludes problems from gasohol: “In modern automobiles, the evaporative emissions system and fuel injection system prevent minor water intrusion issues related to gasohol.
Any issue with gasohol is in engines that sit for extended periods of time, where gasohol may absorb enough water from the air to cause corrosion or combustion problems.”
