by Jim Kerr
Alcohol is a viable fuel for vehicles. Ford Model Ts were run on it during the depression; some drag racers use it, Indy race cars use it, and cars in some overseas countries run on alcohol fuel. In Canada, the auto manufacturers are just starting to design cars that can run on either gasoline or E85 (a mixture or 85-percent ethyl alcohol and 15-percent gasoline). It is relatively easy to modify a vehicle to run on alcohol, although fuel injected vehicles will need a little help from a computer programmer, so why are there no alcohol fuel stations?
The answer is cost! Even though alcohol is manufactured from a renewable resource, and it is fairly simple to manufacture (just ask a moonshiner!), the cost of producing a litre of alcohol is more than the cost of producing a litre of gasoline. As the cost of gasoline rises, producing alcohol for fuel will become economically practical.
There are other disadvantages of using alcohol. The heat content of a litre of alcohol is less than gasoline so more alcohol must be used to achieve the same power levels. The penalty is decreased fuel economy and lower driving range without installing bigger fuel tanks. Another disadvantage of alcohol as a fuel is its lower volatility. During hot weather driving, the fuel vaporises easily and vapour lock (fuel boiling in the lines) can occur. This can make the engine run rough or even prevent it from running. Sealed and pressurised fuel systems on fuel injected vehicles would tend to prevent the fuel from boiling, so this may not be a big concern for modern designs.
There are a couple advantages of alcohol as a fuel. It mixes easily with water and prevents ice formation in cold weather. There is no need to add gas line de-icer. It also has a higher octane rating than gasoline, which allows engine compression ratios to be increased and ignition timing to be advanced for better performance.
Currently, there is only one major fuel company in Canada supplying fuel with alcohol in it. Mohawk sells both regular and premium fuel with a blend of alcohol and gasoline. Advertisements for the fuel claim that up to 40-percent fewer emissions can be obtained by using this fuel. This can be true, but it depends on the age of the vehicle you are driving.
Alcohol is an oxygenate. This means that the alcohol in the fuel breaks down as it is being burned to produce extra oxygen. The extra oxygen combines with the fuel to produce more complete combustion, more power, and lower emissions. However, this process only works well when there is an excess of fuel already entering the engine. Many carburettor-equipped vehicles would produce fewer emissions by using fuel with alcohol in it, but if your engine was already running with a lean fuel mixture, adding alcohol to the fuel can cause a hesitation or stumble.
Fuel injected vehicles use an oxygen sensor to fine-tune the fuel delivery. If fuel with alcohol is used, the oxygen sensor measures the extra oxygen and signals the computer to supply more fuel. The engine should not operate any different or produce fewer emissions in this situation.
Many consumers refer to gasoline and alcohol fuel blends as “Gasohol”. Gasohol got a bad name in the United States during the fuel shortage crisis of the early 1970’s. Some fuel companies were using too much alcohol, or the wrong type of alcohol! This problem has not existed in Canada and has been corrected south of the border.
Two types of alcohol are available for blending with gasoline: ethyl alcohol (grain alcohol) and methyl alcohol (wood alcohol). Ethyl alcohol can be used by itself as a fuel but when it is marketed as a mix with gasoline it is limited to 10% by volume. This is acceptable by most automobile manufacturers. If in doubt, check your owner’s manual.
Methyl alcohol on the other hand is very corrosive. Most manufacturers do not recommend the use of it. Those that allow it specify a maximum of three to five-percent and that anti-corrosion additive must be part of the fuel as well. Fortunately, methyl alcohol is not used with fuel in most of North America. It is just too corrosive.
General Motors did evaluate a fleet of test vehicles in Alberta on M85 fuel (85% methyl alcohol and 15% gasoline) a few years ago. Stainless steel was used for fuel tanks, fuel lines, gauge sending units, and other special parts of the fuel system. This was necessary to resist the corrosive nature of the fuel. The vehicles ran well, but fuel injector problems were frequent because the fuel would attack the conventional gasoline injectors. The test fleet is no longer in service.
Alcohol has the potential to replace gasoline in the future or at least extend our gasoline supply. The successes in development of other alternate energy sources may limit the use of alcohol as a fuel, but there has been some work in using alcohol in conjunction with fuel cells to produce power for tomorrow’s vehicles. Alcohol has been used as a fuel for centuries. Maybe it will be the fuel of the future too.