The Pros and Cons of Ethanol Fuel

Oil Companies Halt E10 Deliveries
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Ethanol is a relatively low-cost alternative fuel, but what are the pros and cons of using ethanol or an ethanol blend in place of unblended gasoline? First, let's review the benefits of ethanol.

Ethanol Pollutes Less

Overall, ethanol is considered to be better for the environment than gasoline. Ethanol-fueled vehicles produce lower carbon monoxide and carbon dioxide emissions, and the same or lower levels of hydrocarbon and oxides of nitrogen emissions.

E85, a blend of 85 percent ethanol and 15 percent gasoline, also has fewer volatile components than gasoline, which means fewer gas emissions from evaporation.

Adding ethanol to gasoline in lower percentages, such as 10 percent ethanol and 90 percent gasoline (E10), reduces carbon monoxide emissions from the gasoline and improves fuel octane.

Ethanol Is Widely Available and Easy to Use

Flexible fuel vehicles that can use E85 are widely available and come in many different styles from most major auto manufacturers. E85 is also widely available at a growing number of stations throughout the United States.

Flexible fuel vehicles have the advantage of being able to use E85, gasoline, or a combination of the two, giving drivers the flexibility to choose the fuel that is most readily available and best suited to their needs.

Ethanol is Good for the Economy

Because ethanol is mostly a product of processed corn, ethanol production supports farmers and creates domestic jobs.

And because ethanol is produced domestically, from domestically grown crops, it reduces U.S. dependence on foreign oil and increases the nation’s energy independence.

Ethanol Lowers the Need for Domestic Oil

Being able to grow ethanol-producing crops reduces the pressure to drill in environmentally-sensitive places like the North Slope of Alaska, the Arctic Ocean, and the Gulf of Mexico.

It can replace to some extent environmentally sensitive shale oil like that coming from the Bakken Shale, and reduce the needs for the construction of new pipelines, like the Dakota Access pipeline.

The Drawbacks of Ethanol

Ethanol and other biofuels are often promoted as clean and lower cost alternatives to gasoline, but of course the production and use of ethanol is not all positives, as there are definite drawbacks: 

  • Vehicles using ethanol blends see a hit in performance, in particular in fuel economy.
  • Creating plant-based biofuels requires a lot of farmland, perhaps too much to be practical or sustainable. Many believe that fertile land should be reserved for growing quality food instead of an industrial commodity.
  • Growing corn for ethanol involves the use of large amounts of synthetic fertilizer and herbicide. Corn production is a frequent source of nutrient and sediment pollution.
  • Depending on how it is calculated, producing ethanol and other biofuels may take more energy than the fuel itself can generate.
  • Damage to carburetors can result from the use of ethanol blended fuels. This is mostly apparent on small motors used seasonally and stored for long periods of time. 

The challenge of growing enough crops to meet the demands of ethanol and/or biodiesel production is significant and, some say, insurmountable.

According to some authorities, producing enough biofuels to enable their widespread adoption could mean converting most of the world’s remaining forests and open spaces to farmland—a sacrifice few people would be willing to make.

“Replacing only five percent of the nation’s diesel consumption with biodiesel would require diverting approximately 60 percent of today’s soy crops to biodiesel production,” says Matthew Brown, an energy consultant and former energy program director at the National Conference of State Legislatures.

In a 2005 study, Cornell University researcher David Pimental factored in the energy needed to grow crops and convert them to biofuels and concluded that producing ethanol from corn required 29 percent more energy than ethanol is capable of generating. Pimental found similar problems with making biodiesel from soybeans.

“There is just no energy benefit to using plant biomass for liquid fuel,” Pimentel says.


Edited by Frederic Beaudry.