Every gallon of gas you buy is already ten percent ethanol — alcohol made from corn. You've been burning corn in your car for years.

Here's what you may not know: a third of the entire U.S. corn crop — five and a half billion bushels a year — goes to making ethanol. Not food. Not animal feed. Fuel.

Ethanol was created as energy policy — a way to reduce dependence on foreign oil. Environmentally, it's roughly a wash — modestly less carbon out the tailpipe, but more fertilizer running off into rivers and streams. Over time, it's become something else: a guaranteed market for a third of America's corn. That supports corn prices, land values, and rural economies. It's an agricultural support program that happens to flow through your gas pump instead of through your taxes.

As electric vehicles grow and gasoline demand declines, that market is shrinking. What replaces it is a question Wisconsin's farm economy will have to answer.

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All regular gasoline is already 10% ethanol. The E10 blend has been the national standard for years. The national average blend reached 10.2% in 2025. Most people never think about it. (American Farm Bureau)

A third of the U.S. corn crop goes to ethanol — about 5.6 billion bushels a year, roughly 33% of total production. (USDA Agricultural Projections to 2035; Oklahoma Farm Report)

E15 is expanding. Wisconsin is one of eight Midwest states (IL, IA, MN, MO, NE, OH, SD, WI) approved for year-round E15 sales starting 2025. E15 is typically 10-30¢/gallon cheaper at the pump, but comes with 1.5-5% lower fuel economy (EPA says 1.5%, independent testers like Car and Driver say 4-5%). The Nationwide Consumer and Fuel Retailer Choice Act of 2025 would make year-round E15 permanent nationwide. (The Gazette; The Drive)

Environmentally, it's complicated. Most lifecycle analyses find corn ethanol produces 20-40% fewer greenhouse gas emissions than gasoline. But growing corn for ethanol uses significant fossil fuel (diesel tractors, natural gas for fertilizer, natural gas for distillation, propane for grain drying). And more corn monoculture means more nitrogen fertilizer runoff into waterways, contributing to the Gulf of Mexico dead zone.

It's not a complete diversion from food. About a third of the corn processed into ethanol comes back as "distillers grains," which are used as animal feed. So the nutritional value isn't entirely lost to fuel production.

The food vs. fuel tension: Yale professor Kenneth Gillingham and University of Minnesota professor Jason Hill have noted that more corn for ethanol means less for feed, potentially raising food prices. (PBS NewsHour)

Ethanol demand faces a shrinking market. EIA projects U.S. gasoline consumption declining through 2035. If blend rates stay near 10.5%, domestic ethanol use could fall from 14.2 billion gallons (2025) to 13.1 billion by 2035 — roughly 400 million fewer bushels of corn demand. (Farm Bureau)

Wisconsin context: Ranked 8th nationally in fuel ethanol production in 2023. The state produces about twice what it consumes. Year-round E15 is now approved. The ethanol industry nationally supports 56,000 direct jobs and contributed $53 billion to GDP in 2024. (EIA Wisconsin State Energy Profile; NCGA)

Related Civic Minute segments: What's in a Gallon of Gas (CM-22), When Gas Goes Up, Everything Goes Up (CM-26), The Math on Electric (CM-35)