This carburetor is an example of corrosion caused by E10 fuel. Photo credit: Tom Shaw.
Annual ethanol targets are scheduled to continually rise until we reach 36 billion gallons in 2022.
If you haven’t noticed by now, most gasoline sold in the United States now contains ethanol. In fact, more than 90% of all gasoline contains up to 10% ethanol. The Environment Protection Agency (EPA) has mandated that ethanol usage in fuel increase from nine billion gallons per year in 2008 to just less than 14 billion gallons in 2013. The mandate is part of the Energy Policy Act of 2005, which was expanded by the Energy Independence and Security Act of 2007. The principle behind the laws was well-intentioned but potentially misplaced—increasing our usage of renewable energy while reducing our dependence on foreign oil.
Year after year, the annual ethanol targets are scheduled to continually rise until we reach 36 billion gallons in 2022. Most of our consumption today is accomplished through the current E10 fuel (90% gasoline, 10% ethanol) commonly found at the pump. Alternatives, such as E85 (85% ethanol, 15% gasoline) for “flex-fuel” vehicles exist as well, but are harder to find in most areas and therefore do not make up the majority of the ethanol usage. It is important to note that gas pump labels for E10 and below are subject to state law. Since a number of states, such as California, don’t require a label, motorists may not be aware that they are putting ethanol in their tank.
Ethanol, as a fuel, has its share of advantages. For example, it can be produced from domestically grown corn or other biofuels that is raised by our own farmers. It can also carry a higher octane rating, assuming it has not been contaminated by absorbing water. For the modern performance enthusiast, E85 has become a popular low-budget race fuel for everything from supercharged modern muscle to turbocharged import vehicles. Some enthusiasts can even be found carrying spare plastic fuel tanks in the back of their vehicles to extend their range between visiting the limited stations that carry E85 fuel. It would seem that a market like ours, with such an emphasis on performance, would welcome ethanol with open arms.
The reality is that there are all types of vehicles and equipment that require pure gasoline. Many were designed long before chemicals, such as ethanol, had been considered during the design and validation processes. Critical components, such as engine seals, gaskets, fuel lines and most internal components, were once tortured on engine dynamometers, scorched in hot weather tests and designed assuming nothing less than 100% gasoline would be cycled through the engine during normal operation. As you can imagine, introducing a new fuel into service can bring a new share of unexpected problems. To start, ethanol is hydroscopic, which means it attracts moisture, which leads to increased levels of water in the fuel system. The current E10 blend has the ability to absorb 0.5% volume before reaching a point where water will actually accumulate outside of the fuel mixture (called phase separation). For a 15-gallon fuel tank, that is about 1.2 cups of water that can be introduced into the fuel and supporting systems. This water formation can lead to metal corrosion and the deterioration of plastics and rubber.
The corrosion issue is most detrimental in carbureted vehicles, which include hot rods, musclecars and a large number of production vehicles. Many of the critical components of a carburetor, such as the main body and float bowls, are die cast from aluminum or zinc. When these materials are exposed to ethanol or the water often contained within ethanol, they create a corrosive combination that can lead to carburetor malfunction and potential failure. In addition, the extra moisture that is introduced into the fuel can lead to buildup or “sludge” that can clog the precision internals of a carburetor responsible for proper fuel delivery. Outside of carburetors, the materials that are commonly used to manufacture gaskets, seals and fuel lines are not consistently manufactured with ethanol-resistant fluorinated polymers. After prolonged exposure to ethanol, these materials can deteriorate, clog fuel filters and result in dangerous fuel leaks.
Today, the EPA and ethanol producers are pushing to allow a 50% increase in ethanol content in gasoline by introducing E15 to more markets. The reason is simple—to meet the federal law’s ever-growing demand for renewable fuels—a demand that cannot be met by E10.
SEMA’s Government Affairs Office is working hard to protect unsuspecting motorists and companies that produce their vehicles and equipment. SEMA is asking that E15 be banned at this time and that the federal law’s renewable fuel mandates be adjusted to reasonable numbers that can be achieved in a free marketplace. Without such a change, E20 and E30 will be the next fuels being pumped into gas tanks.
Need more information? Visit the SEMA Government Affairs homepage to stay up to date. This is one trend that shouldn’t be ignored.