Ethanol vs. Gasoline: Which is better for the environment?

America’s energy future deserves to be fueled by a homegrown, renewable product that is better for the environment than regular, petroleum-based gasoline.

Fortunately, ethanol is a compelling alternative to gasoline, delivering sustainability benefits and reducing environmental impact. Plus, it’s easier on the pocketbook than gasoline, making it a smart and economical choice for a greener future.

This piece debunks common myths and explores the environmental advantages of ethanol as a cleaner, more sustainable fuel option than gasoline and how it can play a pivotal role in a world searching for renewable energy sources.

How is ethanol produced?

Most ethanol is produced from corn. The starch in corn is converted to alcohol via the process shown in this video.

That alcohol (ethanol) is blended with gasoline to provide us with a fuel product that reduces the need for petroleum as well as our reliance on foreign oil.

Iowa leads the U.S. in corn production, and our state also leads the nation in ethanol production, creating nearly 30 percent of U.S. ethanol.

Ethanol production also results in useful co-products like distillers grain, which is fed to livestock.

Because Iowa ranks first nationally in corn production and is also a national leader in livestock production (ranking first in hogs, first in egg-laying chickens, and fourth in cattle on feed), it’s an ideal location for sourcing the corn that becomes ethanol and for utilizing the co-products that result from ethanol production – reducing the need for transportation.

This sustainable cycle benefits Iowa's economy and the environment.

Is ethanol bad for the environment?

Today’s corn-based ethanol reduces greenhouse gas (GHG) emissions by roughly 40 – 50 percent compared to regular gasoline, according to studies by Harvard, USDA and the Department of Energy’s Argonne National Laboratory.

And according to data from USDA ERS and American Farm Bureau, the increased utilization of ethanol and biodiesel (resulting from America’s Renewable Fuels Standard) has resulted in greenhouse gas (GHG) emission reductions that are equivalent to taking 30 million cars off the road.

Yet harmful myths about ethanol persist.

MYTH #1: Ethanol production requires expanded cropland and increased fertilizer use

Contrary to claims that the demand for ethanol necessitates the expansion of cropland and increased fertilizer use, data from the EPA and USDA shows a different reality. 

In recent years, overall U.S. cropland has declined, and corn acreage has remained nearly the same. Looking back even further, USDA data shows farmers are actually planting far fewer corn acres than they were in the early 1900s.

In reality, innovation and efficiency – not expansion – have been the driving forces helping farmers grow enough corn to meet America’s need for ethanol. In the early 2000s, corn yields hovered around 150 bushels per acre. In recent years, yields have increased to nearly 180 bushels per acre, reflecting advances in farming technology rather than an increase in land use.

Advancements in farming technology have enabled farmers to grow more using fewer resources. As of 2022, with the increased use of modern farming techniques, farmers have reduced their use of nitrogen fertilizer per bushel of corn by more than 50% and their use of phosphate and potash by nearly 70% since 1970, according to USDA data. So the amount of fertilizer used to grow a bushel of corn today is actually less than in past decades. 

These insights reveal the growth in ethanol production is not only environmentally sustainable; it also is improving over time with technological advancements on the farm. The ethanol industry is even on track to achieve net-zero carbon emissions before 2050, further reinforcing ethanol’s role as a superior alternative to fossil fuels. 

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MYTH #2: Ethanol leads to higher food prices 

Ethanol production’s impact on the price of food is too often overstated, as our food prices are influenced by an array of complex factors. In general, high food prices faced by consumers today are mostly the result of persistently high inflation. 

Critics of ethanol ignore important facts: 

• Ethanol is created from field corn (which accounts for 99% of corn planted in the U.S.), not the sweet corn consumed directly by humans.
• Ethanol’s primary co-product (distillers grain) is fed to the livestock that provide humans with meat, milk and eggs.
• Raw commodities like corn only account for a small percentage of the price of food.
• Ethanol demand incentivizes increased corn production – stoking innovation and efficiency. 
• Even with ethanol, the U.S. annually produces far more corn than it can use domestically. 

In recent years, the “food vs. fuel” myth has become even easier to debunk: 

• The U.S. has achieved record-setting corn production and has massive amounts of unused corn (nearly 1.76 billion bushels of U.S. corn from 2023 were unused as of September 2024). 
• According to the January 2025 USDA WASDE report, farmers received (on average) a 30% lower price for their corn during the 2023-24 crop year than they did the previous year. And this year (2024-25), corn prices are projected to fall an additional 10%.

In other words, despite an abundant corn supply and low corn prices for farmers, food costs remain high – driven initially by pandemic supply chain disruptions and overall persistent inflation in the economy since then.

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MYTH #3: Ethanol is not energy efficient

Myths about ethanol’s energy efficiency have persisted for decades.

Thanks to technological advancements in ethanol and corn production, for every one unit of energy invested in ethanol production and distribution, roughly three units of energy (on average) are created for ethanol users, according to 2022 analysis by the Renewable Fuels Association. 

These advancements include, but are not limited to:

• Precision farming and biotechnology: Farmers are using less energy and fertilizer to grow a bushel of corn.
• Ethanol plant efficiency: Distillation improvements, more efficient enzymes in fermentation, and even the recycling of carbon dioxide at ethanol plants (utilized for dry ice production, bottling, food processing and other uses) are among the factors that have increased ethanol’s energy efficiency.

As technology advances, ethanol production will become increasingly efficient. 

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In summary, ethanol’s benefits include:

• Energy Independence: Ethanol plays a crucial part in enhancing energy independence by reducing America's reliance on imported oil. In 2023, more than 40% of the oil processed by U.S. refineries came from foreign sources. As a domestically produced renewable fuel, ethanol diversifies our energy supply, helps stabilize fuel prices, and reduces the impact of international market fluctuations on the United States. 
• Sustainable Agriculture: Ethanol production encourages the efficient production of corn (using fewer resources) and creates valuable co-products like distillers grain, which results in a sustainable cycle where less is wasted.
• Reduced Emissions: Today’s corn-based ethanol reduces greenhouse gas (GHG) emissions by roughly 40% – 50% compared to regular gasoline. That GHG reduction is equivalent to taking millions of cars off the road.
• Stronger Communities: Agriculture accounts for 1 in 5 Iowa jobs, and 1 out of every 3 dollars that enters Iowa’s economy comes from agriculture. As a significant contributor to agriculture’s overall impact, ethanol not only supports farmers; it helps all of us who rely on the products farmers provide and the economic activity created by agriculture.