Ethanol in your fuel

You may or may not have noticed but gasoline in our country is now blended with ethanol. If you look closely at the pumps most are now displaying a sticker claiming the fuel is blended with up to ten percent ethanol. Do you care? Should you care?

Why ethanol? The 1990s started the desire to oxygenate gasoline. Concern about ground level ozone and carbon monoxide from vehicles was increasing particularly in big cities. It was known that certain gasoline additives (ones with lots of free oxygen molecules) would oxygenate fuel and make it burn cleaner thus reducing air pollution from vehicles.

Oxygenated gasoline or as it was designated in the United States, reformulated gasoline was legislated as a must in certain large cities under the 1990 Clean Air Act.

Gradually this requirement spread throughout the country.

The additive and oxygenate of choice was MTBE (the real name is long and maybe only interesting to chemists). MTBE was used to increase fuel octane (in place of lead) in the 80s and then more would be added as an oxygenate.

MTBE soon was recognized as a pollutant. Many gas stations had leaking in ground storage tanks and MTBE was showing up in city water systems. It was highly absorptive in water. In some studies it was shown to be a carcinogen.

So oxygenated fuel was now required in large polluted centres but a new oxygenate was required. Ethanol was identified as just that oxygenate. It was found to provide even more oxygen than MTBE. It is also a renewable resource which can be produced from the starch in grains or cellulosic biomass such as wheat straw, corn stalks, sawdust, paper pulp, wood chips. The list goes on. In the United States most ethanol is made from corn due to federal subsidies.

So the idea of oxygenated fuels spread to Canada under many green initiatives and now all fuel suppliers in Canada must average 5% ethanol in their total fuel sales. The final mandate came down from in Federal Government September 1, 2010.

As with many mandates there are many questions as to the benefits of ethanol. That is a much bigger topic.

For the time being you the consumer must learn to live with our current ethanol blended fuels.

Is your vehicle compatible with E10 fuels. Most likely but it will say so in your owners manual.

Ethanol is a strong solvent and also an absorber of water. It therefore requires different fuel system materials. It would eat away certain plastics and rubbers as well as having poor lubricating properties.

Most vehicles have fuel system materials that are happy with ethanol but if you have very old vehicles (1970s and older) they may need some fuel system upgrades.

The water absorption properties of ethanol will cause trouble with gasoline fueled equipment that is not used regularly or goes into storage like boats, lawn mowers, weed whackers , snow mobiles, quads etc. For this type of equipment the use of a fuel stabilizer becomes more important to deal with the extra water that is held in the fuel.

You also may or may not have noticed that your vehicle does not get the fuel economy it used to. The addition of ethanol to fuel reduces its energy content by volume. Real world testing shows a 3% reduction in fuel economy with E10 gasoline. I guess a greener atmosphere always costs the consumer more.

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