How much corn would I need to fuel a cross-country trip with ethanol?

Bags of seed corn.
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With so much volatility in today's world oil market, many are seeking out alternative fuels to power cars. Some, including corn producers, have touted ethanol is a possible alternative fuel. Ethanol, or ethyl alcohol, is made by fermenting and distilling simple sugars from corn. Ethanol is sometimes blended with gasoline to produce gasohol. Ethanol-blended fuels account for 12 percent of all automotive fuels sold in the United States, according to the Renewable Fuels Association. In very pure forms, ethanol can be used as an alternative to gasoline in vehicles modified for its use.

In order to calculate how much corn you would have to grow to produce enough ethanol to fuel a trip across the country, there are a couple of basic factors we have to consider:



  • Let's assume that you drive a Toyota Camry, the best-selling car in America in 2000. We know that the Toyota Camry with automatic transmission gets 30 miles per gallon of gas on the highway.
  • Gasoline is more efficient than ethanol. One gallon of gasoline is equal to 1.5 gallons of ethanol. This means that same Camry would only get about 20 miles to the gallon if it were running on ethanol.
  • We also need to know how far you are traveling: Let's say from Los Angeles to New York, which is 2,774 miles (4,464.2 km), according to
  • Through research performed at Cornell University, we know that 1 acre of land can yield about 7,110 pounds (3,225 kg) of corn, which can be processed into 328 gallons (1240.61 liters) of ethanol. That is about 26.1 pounds (11.84 kg) of corn per gallon.

First, we need to figure out how much fuel we will need:


(METRIC: 4,464.2 km / 8.5 km per liter = 525.2 liters)

We know that it takes 26.1 pounds of corn to make 1 gallon of ethanol, so we can now calculate how many pounds of corn we need to fuel the Camry on its trip:


(METRIC: 525.2 liters * 3.13 kg = 1,642 kg)

You will need to plant a little more than a half an acre of corn to produce enough ethanol to fuel your trip.

According to the research from Cornell, you need about 140 gallons (530 liters) of fossil fuel to plant, grow and harvest an acre of corn. So, even before the corn is converted to ethanol, you're spending about $1.05 per gallon.

"The energy economics get worse at the processing plants, where the grain is crushed and fermented," reads the Cornell report. The corn has to be processed with various enzymes; yeast is added to the mixture to ferment it and make alcohol; the alcohol is then distilled to fuel-grade ethanol that is 85- to 95-percent pure. To produce ethanol that can be used as fuel, it also has to be denatured with a small amount of gasoline.

The final cost of the fuel-grade ethanol is about $1.74 per gallon. (Of course, a lot of variables go into that number.)

For more information on ethanol and fuel economy, check out the links on the next page.