In an effort to reduce pollution, the United States federal government and all 50 states have passed laws encouraging the use of ethanol-blended gasoline.

The Environmental Protection Agency created regulations for implementation of the Energy Independence and Security Act of 2007. These regulations increase ethanol gasoline production to 36 billion gallons by 2022. When the regulations were proposed, the United States was only producing 9 billion gallons. Production of ethanol quickly took off.

In many states, it is nearly impossible to find 100 percent pure gasoline. North and South Dakota, Iowa and parts of Nebraska and Minnesota no longer have access to ethanol-free gasoline. Oklahoma is about to join them.

It is true that ethanol-blended gas burns cleaner than straight gasoline. However, ethanol gasoline creates many problems for owners of older cars, classic cars, marine engines and small gas-powered tools.

Ethanol and corrosion

Ethanol molecules are hygroscopic, this means ethanol attracts and absorbs water, including water from the air. The water levels in ethanol-blended gasoline rise based on humidity, temperature and storage containers. However, ethanol is alcohol, which results in corrosion in the fuel system, thus causing metal parts to rust and plastic parts to crack and malform.

Cars built before 2001 are especially vulnerable to ethanol corrosion. All two-stroke gasoline engines are adversely affected, as are yard tools, marine engines and motorcycles.

Although ethanol on its own is not corrosive, its hygroscopic nature is key to the problem of fuel system corrosion. As ethanol attracts and holds water, it is the perfect medium for growing a bacterium known as Acetobacter in the gas tank. One byproduct from Acetobacter is acetic acid, which causes corrosion within the fuel system.

Most ethanol gas is E10, meaning it has no more than 10 percent ethanol. Recently, a few states started selling E85, which is 85 percent ethanol. The damage from E85 is so well-known that the pumps are labeled for flex fuel cars only.

Fuel systems in cars are the least likely to have problems with corrosion from acetic acid as the gasoline is constantly being used and replaced, leaving little time for Acetobacter to grow. However, when gasoline sits for a bit, the bacteria colonies grow and begin to destroy elements of your fuel system. Fortunately, there are ways to fight ethanol-induced corrosion.

Additives fight corrosion

Whether it is a yard tool, a marine engine or an ATV, when engines with gasoline sit for even a short time — a month or more — the gas becomes stale, and bacteria breed. It is possible to protect a fuel system from corrosion by using additives formulated especially for that purpose.

Not all additives are created equal. Many contain alcohol, and using any additive with alcohol is akin to pouring gas on a burning fire. It only makes matters worse.

Many fuel additives are effective for preventing and treating rust. However, if rust is present, they cannot fix that problem. Regular use of a fuel additive with the ability to absorb water and the ability to prevent rust from forming (many have a bactericide that kills off Acetobacter) with an added protectant is the least expensive way to keep your fuel system running well.

Fuel additives can protect against corrosion, but they cannot remove ethanol from your gas. Since almost all gas has ethanol, corrosion-resistant additives are finding a huge market for their products.

The key is to make consumers aware that even though their cars are not effected by E10 gasoline, their other gasoline-powered items are in danger of ethanol-related rust and corrosion problems.

Ethanol causes other problems in fuel tanks including fuel separation and — since it is burns at a lower temperature than pure gasoline — it is less powerful as a fuel. There are additives on the market that address these and other problems.

In addition, there are combination products available that claim to handle all ethanol-related problems. Unfortunately, there are no studies that test these products head-to-head, so it is unknown if combination products work as well as specifically-targeted additives.