How Does Ethanol Compare to Gasoline?

Basic Differences Between Ethanol and Gasoline

Most automobiles have been powered by unleaded gasoline in recent years, but the combination of ecological changes, an uncertain global political climate and rising fuel costs have led to a search for the fuel of tomorrow. Ethanol is one of the more prominent alternative fuel sources. In today's vehicles, ethanol is most frequently used as the main component in E-85, a blend of 85 percent ethanol and 15 percent unleaded gasoline. The following comparisons are based on tests of E-85 and regular unleaded gasoline.

Differences in Performance

In terms of engine performance and horsepower, E-85 has a measurable edge over gasoline. However, the horsepower advantage of ethanol-based fuels is not significant enough to make any practical difference in pickup and performance.

Differences in Fuel Economy

Gasoline is significantly more efficient than E-85. When it comes to fuel economy, the efficiency of E-85 is approximately 70 percent of that of ordinary unleaded gasoline.

Differences in Ecological Impact

Ecological impact is where E-85 clearly has the upper hand. Although it is essentially the same as unleaded gas in terms of carbon monoxide and harmful hydrocarbons, E-85 emits very little nitrogen oxide. Gasoline and other fossil fuels emit high levels of this greenhouse gas when they burn.

Agricultural Considerations

As a final comparison, it is important to consider the sources of these fuels. Gasoline is harvested from fossil deposits, whereas ethanol is made from agricultural grains. Hypothetically, if ethanol were to catch on as a major, sustained fuel source, huge amounts of farmland would have to be repurposed or established to grow the grains needed to sustain the ethanol fuel industry.
Some agricultural and economic experts have theorized that such an industry would create huge price increases in grains for food and all of their by-products like bread and tortillas. Other theories suggest that it could create farmland shortages. But because such a large ethanol industry is not yet in existence, none of these theories can be proven.