In the United States in the early 2000s, ethanol was hailed as a revolutionary fuel soon to free the U.S. transportation sector from its dependence on foreign oil. Ethanol was not new. Henry Ford imagined it would be the fuel of choice for his new Model T, and Brazil began large-scale ethanol production from sugar cane during the fuel crisis of the 1970s. Much of the initial excitement faded by the latter part of the decade as concerns surfaced about the fuel’s viability long-term and its harmful effect on some engines.
Corrosion
One of the most contentious arguments about higher levels of ethanol in blended fuels is that the fuel corroded engine parts and the tanks that hold it. Ethanol’s corrosive behavior can dislodge materials from the interior of these tanks, bringing those microscopic contaminants into a modern engine’s very sophisticated fuel system.
Additionally, the Indiana Department of Environmental Management commissioned a study to determine the corrosive effects of ethanol on various materials including stainless steel, aluminum and assorted alloys. The study revealed increased pitting, particularly in stainless steel, when exposed to high concentrations of ethanol fuel in a controlled setting.
Engine Wear
Ethanol burns hotter and faster than pure gasoline, leading to concerns of reduced engine life, particularly in small engines and older cars that are not designed with ethanol in mind. Also, plastics and other resins are vulnerable to ethanol’s caustic effects, which imperils fuel injection systems that rely on such materials. The Society of Automotive Engineers discovered repeated failures in pumping equipment used to transport ethanol. In several instances, pumps with a rated lifespan of 2,000 hours failed after just 50 hours.
Water Affinity
Compounding corrosion problems is ethanol’s natural affinity for water. A gallon of ethanol-gasoline blended fuel can absorb up to 4 tsp. of water before phase separation occurs, according to the U.S. Environmental Protection Agency. Phase separation means that after the saturation point is reached, water exists in the fuel as a separate component. The water competes with blended oil in two-stroke engines, such as a marine outboard, negatively impacting lubrication and shortening engine life. That is why the National Marine Manufacturers Association has strongly opposed increasing ethanol percentages in motor fuel.
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