Biofuels are transportation fuels, such as bioethanol and biodiesel, made from biomass — meaning plant material or agricultural, domestic, or industrial bio-based wastes. Some plants used in biofuel production include corn, soy, sunflower, sorghum, and wheat.
Petroleum-based fuels, such as gasoline and diesel, are refined from finite or limited fossil fuel sources. However, biofuels are renewable — meaning more can be produced from a variety of plant-based feedstocks that grow anew each season. Biofuels are a cleaner source of renewable energy.
The combustion of fossil fuels releases carbon into our atmosphere. That carbon has been locked underground in rock for millions of years. Biofuels have lower lifecycle carbon emissions — carbon released when using biofuels is reabsorbed during photosynthesis by the next generation of plant feedstocks as they grow.
Types of biofuels include biodiesel, ethanol, methanol, and butanol.
Ethanol, or bioethanol, is produced from plant matter. As the term suggests, ethanol is another name for ethyl alcohol. It is naturally produced by yeasts in fermentation of sugars. In the United States, ethanol is blended into gasoline at various levels. The most common is E10, a 10% ethanol and 90% gasoline blend, which comprises about 98% of all gasoline sold in the country.
The gasoline alternative E85 and similar high-level blends are designed for flexible fuel vehicles (FFVs). Depending on season and location, E85 may contain 51% to 83% denatured ethanol.
Most recently, the popularity of Unleaded 88 (E15) has grown dramatically. This 15% ethanol-85% gasoline blend may be used in any model year 2001 or later gasoline-capable vehicle.
Ethanol is made by grinding the kernels of field corn into flour. Then, water and heat are added to create a mash. The starch converts into sugar, and the sugars ferment into ethyl alcohol. The alcohol is separated, dried, and denatured. Denaturing fuel ethanol with a small amount of petroleum renders it undrinkable and is required by law. The remaining mash is converted into oil and dried distillers grains with solubles (DDGS), a high-protein animal feed.
On average, one 56-pound bushel of corn produces 2.9 gallons of ethanol, 16 to 18 pounds of DDGS and 0.8 pounds of corn oil. DDGS and oil are valuable co-products used as animal feed and in industries including biodiesel production.
No. Production and use of biofuels can actually decrease fuel and transportation costs, which can be the most expensive part of the food production system and supply chain. According to the World Bank, there is a strong correlation between rising petroleum oil prices and the cost of food.
Many people may not realize that sweet corn, the corn variety humans eat, is only 1% of all corn grown. Field corn is grown for livestock feed and thousands of other uses including the starch feedstock used to make ethanol. A valuable co-product of making ethanol is high-protein animal feed.
No, corn-to-ethanol production does not receive state or federal subsidies. The federal Volumetric Ethanol Excise Tax Credit (commonly called “the blender’s tax credit”) ended in 2011. A Minnesota incentive program, which applied to ethanol biorefineries, ended in 2012.
Incentives that were available in the early days of biofuel development helped build Minnesota into the successful renewable fuel exporter it is today. In 2022, Minnesota’s ethanol industry supported nearly 26,000 jobs and generated $8 billion of economic activity.
Yes. It’s called the energy balance of production. Simply put, it’s the difference between energy inputted and energy resulting.
All forms of energy we use require energy inputs to make them usable and to get that useful energy delivered to us. It costs energy to explore, extract, transport, and refine crude oil. We also must build and maintain the equipment that transfers solar and wind energy into electricity. And we grow, harvest, and ferment plant matter into ethanol and its coproducts.
Estimates of the energy balance of production for U.S. ethanol are better than 2:1. For every unit of energy inputted, more than two units of renewable biofuel and coproducts result. In southern Minnesota, the energy balance of production is estimated to be some of the best at 4:1!
Using ethanol reduces harmful vehicle and greenhouse gas emissions, allowing us to all breathe a little easier. According to a 2021 Harvard/Tufts University study, fuel ethanol produced from corn reduces greenhouse gas emissions by 46% compared to gasoline. Adding ethanol to gasoline can also reduce tailpipe and evaporative emissions of air pollutants such as carbon monoxide, the potent carcinogen benzene, and fine particulate matter that can trigger asthma and other health problems.
Following are several links to research on environmental benefits of fuel ethanol.
Harvard and Tufts University researchers conclude ethanol provides 46% carbon reduction compared to gasoline: Carbon intensity of corn ethanol in the United States: state of the science (2021).
Argonne National Laboratory reports recent improvements in production and emissions reductions: Retrospective analysis of the U.S. corn ethanol industry for 2005–2019: implications for greenhouse gas emission reductions (2021).
USDA and ICF researchers assess emissions benefits: The greenhouse gas benefits of corn ethanol – assessing recent evidence (2019).
USDA summarizes ethanol emissions reductions in this factsheet: USDA Factsheet: Lifecycle Greenhouse Gas Emissions of Corn-Based Ethanol (2017).
The use of biofuels helps reduce our dependence on petroleum, some of which the U.S. imports from other countries. This can also reduce our susceptibility to global disruptions in oil markets.
Most petroleum-based fuels used in Minnesota are produced from crude oil imported from the tar sands of Alberta, Canada. It is some of the most water-, energy-, and carbon-intensive fuel on the planet.
The good news? Minnesota is a national leader in producing biofuels, and we lead the nation in using them to displace petroleum. The U.S. Energy Information Administration reports Minnesota achieved an average blend rate of 12.58% by 2021, the highest renewable fuel content in the U.S.
Minnesota is a national leader in ethanol production. According to a report from the University of Minnesota, the state’s 19 bio-refineries produced 1.34 billion gallons of fuel ethanol in 2022- up 6% over 2021 production.
About 80% of the state’s ethanol is exported, making Minnesota a major exporter of renewable fuels.
Ethanol plants produce more than fuel. Corn oil and high-protein animal feed, called dried distillers grains with solubles (DDGS), are co-products.
According to the university report, Minnesota produced 409 million pounds of corn oil for biodiesel production and poultry and swine feed and 3.95 million tons of DDGS. That’s enough to feed 1.9 million cows, 2.4 million pigs, and 59.3 million turkeys.
Yes. Ethanol “bio-refineries” or plants produce more than fuel.
Corn oil and high-protein animal feed called dried distillers grains with solubles (DDGS) are examples of two important ethanol co-products. Some plants have extra co-products, such as carbon dioxide used by the beverage industry to make dry ice.
A University of Minnesota report estimated that in 2022, the state’s 19 ethanol plants produced 1.34 billion gallons of ethanol. In addition, they produced 409 million pounds of corn oil that was used in biodiesel production and blended into poultry and swine feed as well as 3.95 million tons of DDGS. That’s enough to feed 1.9 million cows, 2.4 million pigs, and 59.3 million turkeys.
In the U.S., ethanol is produced primarily from the starch found in the kernel of field corn.
Presently, one 56-pound bushel of field corn can make 2.9 gallons of ethanol, 16-18 pounds of DDGS, and about 0.8 pounds of corn oil.
That depends.
All motor fuels differ by energy content. Diesel contains more energy per gallon than gasoline, and gasoline is denser than ethanol, propane, and compressed natural gas.
Take a moment to consider real-world fuels we see at our local stations:
E10 gasoline blends: In the U.S., about 98% of all gasoline contains 10% ethanol (E10), which provides environmental, economic, and energy benefits. Will you notice a fuel economy difference using E10 versus non-ethanol gasoline? Unlikely. The energy densities of the fuels are within a few percents of each other, and modern engines adjust to both.
Remember: road conditions, weather, driving habits and carrying extra weight in the trunk (e.g., golf clubs or hockey equipment) affect a vehicle’s fuel economy by 10% to 20%.
Unleaded 88 (E15): The difference in energy density between E15 and regular unleaded is negligible. It’s unlikely you’ll notice any fuel economy difference. Vehicle type, driving conditions, and the blend’s base gasoline will influence actual mileage. Research by the Oak Ridge National Laboratory and the National Renewable Energy Laboratory suggest the effect is on order of one mile per gallon. Some drivers claim better mileage with E15 versus regular unleaded.
Given that E15 is less expensive per gallon than regular unleaded, it can save drivers money. That becomes particularly noticeable as oil prices rise and gasoline prices spike; as we saw during recent price shocks. Across Minnesota, E15 averaged 13 cents less than regular unleaded in 2025, according to the Minnesota Department of Commerce.
E85 and Flex Fuels: On a per-gallon basis, high-blend fuel contains less energy than gasoline. Generally, its lower energy density translates to a 15%-25% decrease in fuel economy or miles per gallon in a flexible fuel vehicle (FFV). But that depends on the FFV model, driving conditions, and driving habits.
However, as all wise FFV drivers know, you must remember the price per gallon! That’s when E85 can really shine. Using E85 may reduce miles per gallon, but it can also lower your cost per mile with its price per gallon.
You might have noticed E85 priced significantly less than gasoline — particularly during times of gasoline price shocks. It is not uncommon to see E85 priced $1 per gallon (or greater) LESS than regular unleaded.
Also remember FFVs are not optimized to E85. Today, they are designed to be “flexible.” The manufacturers know many FFVs will operate only on gasoline, and they build them that way. When engines are optimized to run on high-ethanol blends — IndyCar Racing operates on 100% ethanol fuel (E100) and is a great example — impressive horsepower and performance result!
Everywhere! About 98% of gasoline sold in the U.S. contains 10% ethanol (E10). In Minnesota, E10 has been the fuel of choice for more than 30 years. Let’s go over the basics.
Good Ol’ Regular: Today, all gasoline engines useE10 gasolines. E10 has been used for decades. Regular 87 octane gasoline contains 10% ethanol blended into a “sub-octane” petroleum base that has a rating of 84 octane. Ethanol boosts the resulting octane by three points, achieving the 87 regular gasoline. Mid-grade and premium fuels, such as 91 or 93 octane, are 10% ethanol mixed with gasoline and higher-octane petroleum compounds.
Unleaded 88 (E15): Over recent years, we’ve seen the rise in popularity of E15, often advertised as Unleaded 88 to reflect its 88.5 mid-grade octane rating. Back in 2011, the U.S. Environmental Protection Agency approved E15 use in all 2001 and newer vehicles. This blend has a little more ethanol than the regular E10 we’ve all been using. When sub-octane is the starting base, adding 15% ethanol raises the octane rating by about 4.5 points to 88.5.
Premium and mid-grade gasolines have always cost more than regular unleaded. But, Minnesota Unleaded 88 E15 is less than regular 87.
E85 Flex Fuels: E85 “flex fuel” is a higher ethanol content alternative fuel intended for use in flexible fuel vehicles (FFVs). Like gasoline and diesel suppliers, E85 producers follow specifications to ensure proper performance. Depending on season and location, E85 contains 51% to 83% ethanol and has octane ratings varying from the upper 90s to 100 plus. The U.S. is home to approximately 21 million FFVs and more than 4,000 E85 stations.
More ethanol: Although we won’t find it at retail stations, pure fuel ethanol has an octane rating of 114. That’s more than our sedan, SUV, and pickup engines can use. When engines are optimized to high-level ethanol, as in IndyCar racing, they achieve impressive performance and horsepower.
Yes. The Renewable Fuels Association estimates that 97% of all vehicles on the road today have approval to run on Unleaded 88 E15.
Before it was sold at retail stations, E15 was tested for more than 6 million miles on 86 vehicles of various make, model and year. More than a decade ago, the U.S. Environmental Protection Agency approved E15 use in all vehicles built in 2001 and later.
The U.S. Energy Information Administration defines “octane rating” as the measure of fuel stability. A fuel’s octane rating is based on the pressure at which it spontaneously combusts — pre-ignites — inside a test engine. Pre-ignition is sometimes called “knock” or “ping.”
The name “octane” is shorthand for iso-octane, a knock-resisting petroleum hydrocarbon that is a 100 on the octane rating scale. The octane of most regular gasoline is 87. Mid-grade fuels will be in the 88-90 range and premium gasoline ratings are usually 91-93. You may see expensive specialty fuels for sale, such as racing gas or aviation gas, with octane ratings in the high 90s to well over 100.
When used in an engine designed for it, higher octane fuels can mean more horsepower and engine efficiency. Ethanol has a naturally high octane rating of approximately 114, while the base gasoline used to make our fuels is 84 (called sub-octane). As an example, fuel suppliers add 10% ethanol to sub-octane base gasolines to make 87 octane regular E10.
Automakers are building smaller, higher-compression engines to reduce weight and meet more stringent fuel economy standards. Engine compression, or pressure inside internal combustion engine cylinders, translates to thermal efficiency and work from a volume of fuel. Higher-octane fuels allow for optimization of performance and emissions in high-compression engines.
We have two primary sources of octane. One is renewable ethanol, derived from bio-based materials like starch in field corn and sugarcane. The other is carcinogenic BTEX toxins (benzene, toluene, ethylbenzene, and xylene) produced from crude oil.
“Flex Fuel” can refer to either flex fuel vehicles (FFVs) or a high-blend ethanol fuel designed for use in FFVs. The gasoline alternative E85 is by definition an alternative fuel — similar to propane, electricity, or compressed natural gas. Depending on the season and location, the content of E85 will vary from 51% to 83% ethanol. You may see other mid-level flex fuels for sale such as E30 or E50, but all are intended for use in FFVs.
FFVs have specially designed fuel systems that adjust to any level of fuel ethanol from 0% to 85%. About 21 million FFVs are on U.S. roadways with about 550,000 registered in Minnesota. For years, FFVs have been sold as standard equipment with no added cost. Owning an FFV provides a choice of fuels at the pump — especially during oil shocks when gasoline prices spike. Minnesota has led the nation in the number of stations offering E85 and in use of the fuel since the late 1990s when the Twin Cities metro area was selected as a U.S. Department of Energy test market.
To determine if your vehicle is an FFV, check inside the fuel door for a decal indicating that you may use “E85” or “Ethanol Fuel”. Some automakers use yellow fuel caps, external badges, and/or window decals to identify FFV models. If it is still unclear whether your vehicle is an FFV, every manufacturer’s unique engine code within the vehicle identification number (VIN) will indicate the model. The Renewable Fuels Association list of historical FFV models can help. For recent models, the federal Alternative Fuels Data Center provides a searchable list.
Regardless of the make and model, recreational boat motors in the U.S. are approved to run on E10. The National Boat Racing Association (NBRA) and Crappie Masters both use E10 for races and fishing competitions. Ethanol is anhydrous, meaning it does NOT contain water. With any boating fuel, you must keep storage tanks clean and moisture-free to ensure proper operation. All gasolines have a shelf life of 90 days, and it is never recommended to store them from one summer to the next.
Unleaded 88 (E15) and flex fuel ethanol blends like E85 are not intended for use in small engines. Stick with E10 for your boat.
Yes. All small engines sold in the U.S. have been designed for use of gasoline containing up to 10% ethanol (E10). Ninety-eight percent of all U.S. gasoline sold today is E10, and for more than 30 years, E10 has been the gasoline of choice in Minnesota. Whether you need to mow the lawn, cut firewood, or blow some snow, E10 is a smart choice.
Unleaded 88 (E15) and high-level flex fuel ethanol blends like E85 are not intended for use in small engines. Stick with E10 for your small engines!
Ethanol is produced here in Minnesota. Unlike oil, we can make more of it; but does that translate to lowering our fuel prices? Yes.
The Minnesota Department of Commerce reported that Unleaded 88 (E15) averaged 13 cents per gallon less than regular unleaded in 2025. When high oil prices slammed the economy in 2022, every penny per gallon mattered. E15 can provide a welcome respite.
The Renewable Fuels Association estimates that 97% of all gasoline vehicles on the road are approved to run on E15.
Warranties usually cover specified components of vehicle systems for repair or replacement over a limited time and miles driven — such as three years and 36,000 miles. Vehicle warranties do not cover fuel.
More than a decade ago, the U.S. Environmental Protection Agency approved E15 use in all gasoline vehicles built in model year 2001 and later. Check your vehicle’s specific warranty information for more.
No. Ethanol can absorb water. However, it does not “pull” water out of the air.
Ethanol in a fuel, such as an E10 blend, can absorb small amounts of water that may be inside the fuel tank. When this occurs, it is harmlessly removed as the fuel is burned within the engine.
Water contamination inside any fuel tank should be avoided. With non-ethanol fuels, the petroleum portion will float on top of the contamination if water is in the tank. If more water enters, the fuel will continue to float. Eventually, this adversely affects fuel outlets and pumps that are set at the low point of the tank. That tank needs to be drained and cleaned.
Ethanol blends can absorb small amounts of water if they get into the tank. Higher level blends will lead to higher amounts of water. However, if too much water contamination has occurred, the fuel can undergo “phase separation” — separating into levels of gasoline, water, and water-ethanol mix. Just as in the non-ethanol fuel example, it results in the tank needing to be drained.
The takeaway? Avoid water contamination in any fuel tank. Keep in mind that consistent use of ethanol-blended fuel can actually help keep your fuel tank dry and clean. Minnesota gasoline has been E10 for more than 30 years. Rarely do we ever hear about phase separation.