Tuesday, July 23, 2024 Detailed Auto Topics
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The idea of ethanol, as a motor fuel, is not new. Henry Ford’s 1896 Quadicycle ran on grain alcohol or ethanol. Early Model T Fords run on ethanol, gasoline or a blend. The U.S. Army even produced and used ethanol as a fuel, in the 1940's. Because of the overwhelming advantages that pure gasoline offers, ethanol virtually disappeared, until recently.

Ethanol in motor fuel is a controversial topic. Proponents tout all sorts of proposed benefits while opponents blame it for a huge range of problems. Useful facts are in very short supply.

Ethanol is neither all good nor all bad

Love it or hate it, ethanol is likely to be around for quite a while. The information in circulation has largely overstated both the benefits and threats of ethanol. Ethanol is not without benefits and it does also cause issues. Understanding the product can help avoid many problems.

Advantages from ethanol fuel

Ethanol burns more slowly than gasoline. The effect is much like addition of an octane to the fuel. They design many race engines to run on ethanol. Because they equip such engines to use it as a fuel, they produce great deal of power.

Some believe adding ethanol to gasoline reduces carbon dioxide. Scientific data have not backed this and testing continues. Ethanol is also a very good cleaner and is the main component in many fuel injection cleaners.

Problems with ethanol as a motor fuel

Ethanol provides less miles per gallon than gasoline

Pure gasoline produces more than 116,000 BTU of heat per gallon. With ethanol, we produce 76,330 BTU per gallon. We produce 33% less energy, so it takes more gallons to power a vehicle. With E-10 or 10% ethanol, mileage will normally drop more than 3%. As the percentage of ethanol increases the drop in mileage gets worse.

They equip modern vehicles to run on ethanol blended fuel, and the computer will reset the fuel injectors, based on the alcohol content. Older vehicles may need to be re-tuned. For instance, because of the lower energy content, an older engine may run too lean. This can cause detonation and damage to the engine.

Increasing the carburetor jet size slightly can help eliminate this problem. Increasing the timing slightly may also be possible, as ethanol burns more slowly than gasoline.

Precautions when using ethanol fuel

Certain precautions make ethanol use much less problematic. These are especially important in older vehicles and small engines. As the percentage of ethanol increases, these are much more critical.

Phase-separation in old ethanol fuel

Alcohol has an affinity for moisture. Water is drawn from the atmosphere and enters the fuel. Unfortunately, as moisture increases, the ethanol bonds to it and separates from the fuel. We call this phase-separation and it is a big problem. The water attacks the metal in the fuel tank. If enough water accumulates, submersion of the fuel-pump-pickup occurs. When this happens, the vehicle will not run.

Phase separation and rusting in old ethanol fuel

Ethanol fuel must never be kept more than three months

Inside view of a rusted fuel tank

Keeping the fuel tank full will help keep air out and reduce moisture available to the ethanol. This also pertains to any containers used to store fuel. The short shelf-life for ethanol, creates a problem for vehicles not driven every day. Having to keep a full tank and the requirement to replace fuel every three months, can be expensive.

The same thing can also occur in the carburetor bowl. Once the fuel separates, water and ethanol will attack the metal components. Driving vehicles every day has always been important, but with ethanol fuel, this is far more critical.

Replacing the fuel lines and the tank may be necessary on older vehicles

Modern vehicles have ethanol resistant fuel lines. Older vehicles will need their lines replaced with modern materials to hold up. Ethanol resistant hoses and nylon fuel line does a great job. Classic cars, built before 1985 have fuel systems that are very straightforward. Replacing fuel lines on these older vehicles should present little problems.

Far more problems arise with early fuel-injected models. These have far more complex fuel systems. Their design is for gasoline and not ethanol use. Many domestic manufacturers have discontinued these components. Reconstructing these fuel delivery systems are very difficult and quality replacement parts are hard to find. Keeping these vehicles running may get very expensive, if ethanol levels increase.

Ethanol also damages fiberglass fuel tanks. Stainless steel is the best choice for replacement. Mild steel may also work, but the fuel needs to be kept very fresh to prevent rust. Aluminum is not a good choice. Moisture and ethanol will quickly corrode reactive metals.

Accelerator pumps, in the carburetor, are another problem. Rubber pumps will not last long. Leather replacements are available for some vintage vehicles and will give good service.

On older vehicles, it is a wise precaution to add an extra fuel filter, between the fuel pump and the carburetor. This will help trap any debris picked up by the fuel. Remember ethanol is a great cleaner, any rust or debris in the tank may be picked up and transported through the fuel.

Beware of fuel additives

Fuel additives are largely ineffective and may cause problems

Additives claiming to counteract ethanol are largely ineffective and may cause problems. Most fuel system cleaners and injector cleaners contain alcohol. Adding these to the fuel system may only increase ethanol in the fuel. An exception is a fuel stabilizer. When added to fuel that is fresh, it can help with phase separation. This does NOT extend the shelf life beyond three months, but can help a premature breakdown of the fuel.

No law requires the addition of ethanol to the fuel we buy

They have passed several laws to encourage the use of ‘alternative fuels.’ Ethanol in standard fuel is usually 10% or less, but 15% E-15 may be on the horizon. This increase makes the cautions in this article far more critical.

Fuel distributors may receive up to fifty-one cents a gallon, for the ethanol they sell. This is a powerful incentive and can lead to problems. Mixing more than 10% in each gallon, can produce a large profit. Distributors are also free to sell fuel without additional ethanol added, but they receive no subsidy. Stations still sell ethanol-free fuel, but they may take effort to find.

Ethanol is not likely to disappear soon, nor is it the end of older vehicles. Making the needed changes and using only fresh fuel will help prevent most problems.

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