The great ethanol debate

When it comes to ethanol (aka E85), there's no shortage of disagreement over its viability as a fuel source.

The federal government has been promoting ethanol for decades as a renewable, homegrown alternative to gasoline. In recent years, this alternative fuel has resonated with consumers who are concerned with America's dependence on foreign oil as well as pump-price volatility. But is Ethanol the answer?

Michael Pacheco, a spokesman for the National Renewable Energy Laboratory in Golden, Colo., explains: "The big challenge is that we are going to reach a peak in world oil production," he says. "We need to start working toward replacement fuels 20 years before that peak."

The near-term advantages of ethanol look promising to government scientists as we draw closer to that peak, because it can be produced in large quantities, and it requires fewer technological breakthroughs and less infrastructure development than is needed to support electric vehicles and fuel cell vehicles.

Yet university scientists for decades have raised questions about ethanol's viability as a fuel source for three reasons:

• They argue that it is unethical to produce fuel from a food crop, especially if it drives up food prices. Most of the ethanol in the United States is made from corn.
• Ethanol contains less energy than gasoline, and it takes a lot of energy to produce.
• A variety of conflicting studies have shown that producing ethanol may—or may not—increase emissions of carbon-dioxide, a gas linked to global warming.

Putting E85 to the test

To better judge ethanol's strengths and weaknesses, we decided to buy a flex-fuel vehicle (FFV) and put E85 to the test. E85 is an ethanol mixture promoted as an alternative to gasoline.

We put our 2007 Chevrolet Tahoe FFV through our full series of fuel-economy and acceleration tests while running on each fuel (see our test results). When running on E85 there was no significant change in acceleration. Fuel economy, however, dropped across the board. In highway driving, gas mileage decreased from 21 to 15 mpg; in city driving, it dropped from 9 to 7 mpg. You could expect a similar decrease in gas mileage in any current FFV.

We also took our Tahoe to a state-certified emissions-test facility near our test track in Connecticut and had a standard emissions test performed. We found a significant decrease in smog-forming oxides of nitrogen when using E85. However, ethanol emits acetaldehyde, which the EPA lists as a probable carcinogen and something that standard emissions-testing equipment is not designed to measure. But that might be a relatively minor evil, however.

"Acetaldehyde is bad," says James Cannon, president of Energy Futures, an alternative-transportation publication, "but not nearly as bad as some of the emissions from gasoline."

Before we could do any of that though, we had to fill up our Tahoe with E85, which was no easy task. We found it's especially difficult to get E85 in New England, near our test track. After trying all the local channels, we ended up having to mix it ourselves.

Yet, for some consumers, such as those who live in the Midwest, near where corn is grown and ethanol is produced, the fuel does offer perhaps the only readily available alternative to petroleum today.

So how did we get to the point where the government is subsidizing a fuel that gets worse fuel economy and is difficult to buy?

The ethanol story is both complex and controversial. In the following pages, we'll dig more deeply into the pros and cons of ethanol, learn more about how ethanol works, the government's support for it and its unintended consequences, ethanol's environmental impact, and issues with ethanol for consumers, and the future of ethanol.