Ethanol Report 2012

Beware of New Ethanol Blend

Millions of Vehicle Warranties and Safety of Small Engine Users at Risk

The government's decision to allow sale of gasoline blended with up to 15 percent ethanol, so-called E15, means that one of these days you'll likely pull into a gas station that could have as many as four pumps with different kinds of fuel: one for E10 (up to 10 percent ethanol); one for E15; possibly one for E85 (between 70 and 85 percent ethanol); and maybe one for pure gasoline.

Depending on how old your car or truck is, you'll have to make sure you choose the right blend. If you make a mistake and put E15 in an older car, there's a good chance you'll run into big problems with your engine. And if you fill a gas can and use it in your lawnmower or outboard, be prepared to buy a new one soon.

In early 2011, the Environmental Protection Agency approved the corn ethanol industry's petition to increase the amount of ethanol that can be blended with gasoline. EPA approved E15 for use in newer cars and trucks – Model Year 2001 or later. That's a 50 percent increase in the amount of ethanol allowed in the widely available E10.

Every major automaker has warned that their warranties – even for newer vehicles – will be voided if drivers fill up with E15. Automakers and small engine manufacturers are so upset that they are suing EPA over the E15 decision. Click here to see the letters that major auto companies sent to Rep. Sensenbrenner (R-Wis.) before a July 2011 Congressional hearing (where EWG's Heather White testified about the problems with E15).

Here are a few highlights from the letters to Rep. Sensenbrenner:



“Vehicle engines were not designed or built to accommodate the higher concentrations of ethanol. . . . There appears to be the potential for engine failure.”
[Read more...]




“Ford does not support the introduction of E15 into the marketplace for the legacy fleet… Fuel not approved in the owner’s manual is considered misfueling and any damage resulting from misfueling is not covered by the warranty.”
[Read more...]


General Motors

General Motors

“It is clear to us, as it is to others, that the controls envisioned by EPA will not prevent such mis-fueling situations from occurring.”
[Read more... ]




“Toyota cannot recommend the use of fuel with greater than E10 for Toyota vehicles currently on the road . . . .Our policy remains that we will not provide warranty coverage for issues arising from the misuse of fuels that exceed specified limits.”
[Read more... ]


EWG had called automakers a few months earlier and gotten similar responses.

Automakers aren't the only ones worried about engine trouble with E15. Several gasoline refiners, including QuickTripValero Energy Corp., Marathon Oil Corp. and Tesoro Corp., have said they won't sell E15 for the foreseeable future. The American Automobile Association AAA and the Coast Guard have warned consumers about problems they could encounter if they use E15.

Since ethanol is more corrosive and burns hotter than gasoline, it may cause higher rates of engine stalling, misfiring and overheating. Other effects include higher nitrous oxide and formaldehyde emissions, lower gas mileage and damaging fuel tanks and pumps.

To make sure you don't accidentally void your vehicle's warranty or ruin your lawnmower, chainsaw or outboard motor, see EWG's E15 consumer guides. [Read more...]

To download our handy wallet-sized guide to see which ethanol blend is compatible with your vehicle, click here.

To learn more about the new E15 label on gas station pumps, click here.

Ethanol Guide

Which blend to choose?

download wallet guide


EWG's handy wallet-sized card lists various ethanol blends and which vehicles/engines can safely use them. Click here to print.

If you are interested in the dangers of higher ethanol blends to your health and your engine's performance, read EWG's report about transportation fuel that is 15 percent ethanol, known as E15. Since ethanol is more corrosive than gasoline, two studies by the National Renewable Energy Laboratory have found that E15 may cause valves to crack, certain air emissions to increase, engine temperatures to rise and fuel efficiency to fall.1 2

Ethanol Facts

EWG’s Guide to Understanding Ethanol

paying at the gas pump


We all want to reduce dependence on fossil fuels and conserve natural resources. But using corn ethanol as transportation fuel is not the answer. Adding small, well-tested amounts of oxygenated additives like ethanol to engine fuel can reduce air pollution in targeted areas. This practice makes sense. But the corn lobby’s efforts to cast corn ethanol as an alternative transportation fuel is misleading.

Environmental Working Group’s numerous analyses have shown that corn ethanol:

  • Does not significantly reduce American dependence on foreign oil.
  • Contributes to higher food prices.
  • Harms the environment.

Advanced biofuels, like those derived from perennial grasses, wood chips, or agricultural residues, are intended to conserve natural resources and not compete with the food supply. However, these so-called second generation biofuels are not yet on the market. Industry proponents claim they are “just around the corner,” but production is currently still in the early phases. EWG advises drivers to seek environmentally-responsible alternatives. They should use public transportation whenever possible and drive less. For tips to reduce your gasoline consumption and save money, click here.

What is ethanol?

Ethanol is a clear, colorless liquid made from starches like corn, sugar-laden plants such as sugarcane or cellulosic feedstocks made from grasses, agricultural residues like corn cobs and wood chips. Ethanol can be found in alcoholic beverages. It is also an industrial solvent. When mixed with gasoline, it can be used to fuel vehicles and other engines. As a fuel, it is more corrosive than gasoline. When fuel blends that contain more than 10 percent ethanol are used in small engines, they run hotter than pure gasoline. Engine damage or failure can result.

Why is ethanol added to gasoline?

Ethanol powered the original Ford Model T, produced in the early 1900s. Prohibition forced car makers to switch to gasoline so that ethanol fuel wouldn’t be diverted to illegal use in intoxicating beverages. From the 1940s to the late 1970s, the automotive industry continued to rely on gasoline to power internal combustion engines because gas was cheaper than ethanol.

In 1979, the federal government ordered the gasoline industry to remove toxic lead from fuel to reduce air pollution. Gasoline makers substituted methyl tertiary butyl ether (MTBE) to boost the oxygen content of gasoline to help the fuel burn more completely and prevent engine knocking, but the additive caused underground gasoline storage tanks to corrode, leaking MTBE into groundwater. Many states banned MTBE. In the early 2000s gasoline blenders began using small quantities of ethanol as a substitute booster to increase the fuel’s oxygen content.

Over the last decade, a maze of energy and tax legislation designed to reduce America’s dependence on imported oil and fossil fuels has created incentives for ethanol production.
As a strategy to promote energy independence, in 2005, Congress enacted the federal Renewable Fuel Standard, requiring escalating production of ethanol, mainly from corn, to be blended into vehicle fuel. In 2005, the nation produced about 4 billion gallons of ethanol. In the 2007 energy bill, Congress greatly expanded the mandate by requiring fuel blenders to use 15 billion gallons of conventional biofuels (mainly corn ethanol) by 2015 and an additional 21 billion gallons of so-called second generation or advanced biofuels by 2022. The latter requirement contemplated that by 2010, the advanced biofuels industry would have taken off.

But that has not happened due to economic and technological barriers. Consequently, corn ethanol is the only domestically produced biofuel that is available in large quantities; this is unlikely to change in the near future.

Is all gasoline blended with ethanol?

Most American vehicle fuel is a mix of 90 percent gasoline and 10 percent ethanol. This mix is known as E10.

Ethanol industry lobbyists, eager to maximize industry profits, advocate fuel blends greater than 10 percent ethanol. They argue that automotive fuel is about to hit a “blend wall,” defined as the point at which more ethanol is produced than the market for E10 engine fuel can absorb. To sell more ethanol, these lobbyists have pressed for federal government approval to sell E15 fuel. To achieve that goal, they had to secure permission from the Environmental Protection Agency under the federal Clean Air Act. Last year, the EPA approved the sale of 15 percent ethanol blends, called E15, but only for cars manufactured in 2001 and later.3

Drivers and engine owners who disregard EPA’s directions to use E15 only in newer cars may find that older vehicles and small gasoline engines such as motors for boats, chain saws, snowmobile and leaf blowers incur serious damages. Since ethanol is a solvent, the E15 mix can corrode some fuel system parts, especially pumps and hoses. It also eats away at standard storage tanks and pipelines.

What is a flex fuel car?

The ethanol lobby is promoting increased sales of “flex fuel” vehicles that can run on up to 85 percent ethanol, known as E85. But most owners of flex-fuel cars don’t fill them up with E85 because the more ethanol in fuel, the lower the vehicle’s gas mileage. Flex-fuel vehicles running on E85 will get about 27 percent lower gas mileage than with gasoline. The price of E85 doesn’t always compensate for lost fuel efficiency.

Is all ethanol made from corn?

Most ethanol in the U.S. is produced from corn, but Brazil and some other countries use sugarcane as the primary feedstock.

Is all corn ethanol made to mix with gasoline?

Yes. But distiller’s grain, a by-product of corn ethanol production, can be fed to livestock. Other by-products of corn ethanol production include corn oil, corn meal and corn syrup.

Is ethanol better for the environment than gasoline?

The direct and indirect damage to the environment of corn and corn ethanol production outweigh any minimal benefits. Sensitive land like grassed buffers, streambanks and wetlands are being planted with corn to fulfil federal ethanol mandates and maximize corn growers’ profits.

Many U.S. ethanol refineries are powered by coal, hardly the most environmentally-friendly option. Current ethanol production systems may actually emit more greenhouse gases than gasoline.3

Growing corn to make ethanol production requires significant amounts of water, fertilizer and pesticides that can pollute soil and waterways. Corn production consumes fossil fuels: diesel fuel powers tractors, combines and trucks during planting, harvest and shipping. A recent National Research Council report found that corn ethanol uses significantly more water in its production cycle than gasoline.4

What is the impact of ethanol on food prices?

Diverting some corn from food and feed to fuel pushes up food prices. Poor people in developing countries spend a larger percentage of their income on food, so they are disproportionately penalized by rising food costs.5 In 2011, 40 percent of the U.S. corn crop was used to produce ethanol. The expansion of the corn ethanol market increased corn prices by 36 percent from 2006 to 2009.6

Has ethanol use reduced America's dependence on foreign oil?

No. Corn ethanol has displaced only three to four percent of gasoline imported into the U.S.7 Americans could displace that much gasoline by keeping tires properly inflated, using the right grade of motor fuel and obeying speed limits.

Are there alternatives to ethanol?

Yes. There are other ways to power or fuel a vehicle, including electricity, hybrids, battery technology, hydrogen, biodiesel and other biofuels like biobutanol that can be made from more sustainable sources. But there is no easy answer. If the electricity for an electric car originates at a coal-fired power plant, its share of carbon emissions can be hefty.

Some companies are developing “drop-in biofuels,” defined as biofuels that behave like gasoline and use existing infrastructure like gas pumps and storage tanks. These can be refined from potentially sustainable sources like wood and agricultural residues. The use of some biofuels may not reduce automotive gas mileage. But such fuels are still in the research stage. Much more work must be done before they are developed for the mass market.

What fuel should I buy for my car?

That depends on the type and age of your vehicle and whether you can accept ethanol’s lower gas mileage. The EPA says that E15 should only be used in 2001 and later model year vehicles. However, every major carmaker has said that pumping E15 into these vehicle models may void the manufacturer warranty.

EWG has produced a handy wallet-sized card that lists which vehicles/engines can safely use which ethanol blends. The list of engines that can’t run on higher blends of ethanol is much longer than the list of those that can. Consumers should always check their owner’s manuals for specifics.

Print a copy of the guide by clicking here.

What fuel should I buy for my lawnmower, outboard motor, ATV, or other small engine?

To be safe, stick with regular unleaded gasoline – and hope you can find it. Check with your engine manufacturer or mechanic to find out if your engine can safely run on E10, E15 or other ethanol blends. The U.S. Coast Guard has opposed the introduction of E15 into the nation's fuel supply because higher ethanol blends could cause marine engines to stall and leave boaters adrift.

Some small engines lack an oxygen sensor feedback control and cannot compensate for the higher oxygen content in higher ethanol blends. As a result, engines operating under the oxygen-rich conditions caused by high ethanol content can quickly overheat.

How do I know how much ethanol is in the gasoline I am purchasing?

Not every state requires gas pumps to be labelled with the amount of ethanol the fuel contains. In some states, service stations can pass off E10 as regular gasoline. If you cannot find a label, ask a service station employee. If a pump says E85, the blend could range from 70 to 85 percent ethanol, depending on the retailer and seasonal adjustments. Engine operators who need precise information can buy fuel testing kits.

What are the politics behind corn ethanol?

It makes sense to add small, well-tested amounts of oxygenated additives such as ethanol to engine fuel to reduce air pollution in areas out of compliance with federal regulations.

But the misguided effort to treat ethanol as an alternative transportation fuel has become a well-founded source of concern for consumers, environmental groups, livestock farmers, automobile makers, the anti-hunger community and the food industry.

For several years, ethanol producers and their lobbyists have been pushing for incentives to increase production beyond U.S. market needs. They have persuaded some lawmakers to support their cause, but increasingly the public has resisted because of ethanol's downsides. Click here to read a letter opposing extension of the ethanol tax credit, signed by EWG and 89 other groups. On June 16, 2011, the U.S. Senate acted on our recommendation and voted to repeal the ethanol tax credit and tariff by an overwhelming vote of 73 to 27.

How can I learn more?

Click here to learn about dangers posed by higher ethanol blends to your health and your engine's performance.

To find out more about E15, see EWG's other work:

  1. EWG press release on EPA's E15 labeling decision -
  2. EWG testimony before the House Committee on Science, Space and Technology on July 7, 2011, about E15 – documents/hearings/070711_White.pdf
  3. EWG blog on vehicle emission testing data -
  4. EWG blog on automakers' responses to questions about using E15 and its effect on vehicle warranties –
  5. EWG blog on proposed labels for E15 -
  6. EWG blog on the ethanol industry's push to force consumers to use E15 -

Other useful links:

  1. EPA's Green Vehicle Guide lists greenhouse gas emissions and air pollution scores, gas mileage, fuel use types, etc. for a wide range of vehicles. Be aware that the fuel economy estimates are not accurate if you fill up with ethanol blends because of their lower gas mileage. EWG has urged EPA to update its guide to specify whether vehicles can use E15 and other ethanol blends, but it has have not done so –
  2. EPA and the Department of Energy's (DOE) Energy Efficiency and Renewable Energy website lists greenhouse gas emissions and air pollution ratings, gas mileage, fuel costs, safety information, etc. for new and used vehicles –
  3. DOE's Energy Efficiency and Renewable Energy website details federal and state incentives and laws on renewable fuels, hybrid and electric cars, public agency fleet requirements, climate change initiatives, air quality improvement incentives, etc. –
  4. This website lists service stations in the U.S. and Canada that do not sell ethanol -
  5. This website lists state ethanol labeling laws (not updated since 2009) –

Ethanol Labels

New Label at the Gas Pump

As a condition of approving 15 percent ethanol (E15), the Environmental Protection Agency has issued a new ethanol label (below) that gas stations will be required to post on their pumps. When the policy takes effect, a label like this one may appear at your local service station if the owners decide to sell this new fuel.

E15 warning label


The Renewable Fuels Association, an ethanol lobbying group, is handing out these free E15 labels to gasoline stations. Its move marks a course reversal from its previous position, as late as November 2010, opposing ethanol labels on gasoline pumps. The National Corn Growers Association has opposed ALL ethanol labels on grounds they “can lead to general consumer confusion.”

In early 2011, while the ethanol industry was lobbying to limit consumer disclosure, EWG asked EPA to authorize a more detailed label to give consumers even more information. The agency, under pressure from the ethanol lobby, rejected many of our recommendations. See our blog post for more on this topic.

EWG's proposed label:

proposed ewg ethanol warning label


Here are other ethanol labels you may encounter. Service stations can voluntarily place them on pumps. Federal regulation does not require gasoline stations to consistently label ethanol blends other than E15.

Examples of current voluntary ethanol labels:

examples of voluntary warning labels for ethanol fuel



Ethanol Tips

Easy Ways to Save Money & Reduce Gas Consumption

A few simple steps can save money on gas – and reduce your emissions – more than you might realize. The single most effective thing you can do is to drive a hybrid or electric vehicle that uses little or no gas. If that's not feasible, here's how you can cut the economic and environmental costs of driving.

1. Maintain your vehicle properly

  • Keep tires inflated to the recommended pressure.
  • Use the right grade of motor oil (check the manual).
  • Replace air filters when you change oil (your engine will run more efficiently).
  • Replace worn spark plugs.
  • Repair leaks from engine oil or other fluids.

2. Drive the speed limit and don't accelerate too fast or brake too hard

3. Minimize air conditioner use

Turn your engine off when idling for long preriods


5. Get rid of excess weight in your vehicle


6. Drive Less

  • Plan ahead to combine errands and other trips.
  • Carpool when you can.
  • Live close to work if possible or telecommute.

7. Use alternative transportation

  • Take public transportation (bus, train, subway, etc.) if available.
  • Walk, run or bike. You'll be healthier, too!

How Ethanol Pollutes

Ethanol's Environmental Costs

Since 2005, the U.S. government has mandated that gasoline refiners blend increasing amounts of ethanol into their fuel.

In its marketing, advertising and lobbying, the corn ethanol industry has made strenuous efforts to cast corn ethanol as an environmentally friendly alternative to petroleum-based gasoline. That claim is deeply misleading.

Today, 40 percent of the U.S. corn crop is being used for ethanol production, creating a dismaying array of environmental costs and unintended consequences. Corn acreage has expanded from 80 million acres at the beginning of the ethanol boom to 92 million acres as farmers tried to meet the demand and take advantage of record high corn prices. New cornfields are popping up in already water-short areas such as western Nebraska and South Dakota. Despite this, corn yields continue to lag behind industry projections, so producers have been tearing up pastures, draining wetlands, tilling grassed waterways and even converting community golf courses to corn production.

In addition, farmers stopped annual rotations with wheat, soybeans and other crops, which depletes the soil. And since corn is one of the most energy-intensive crops, growers apply comparatively more chemical fertilizers and pesticides. Unfortunately, efforts to preserve precious wildlife habitat and conserve soil and water resources have been put on the back burner, leading to headline-making problems of erosion and water pollution. Government experts estimate that U.S. municipalities spend $4.8 billion per year to remove nitrates from drinking water supplies; about $1.7 billion of that spending is traceable to runoff from agricultural fertilizers. Check out EWG's Losing Ground report to learn more.

dead zone


The pollution doesn't end there.

Nitrogen fertilizer and pesticide runoff wash down the Mississippi to the Gulf of Mexico, where a dead zone the size of New Jersey chokes off oxygen to marine life every year. Similar damage is being done to the Chesapeake Bay, threatening the health of the nation's most renowned estuary. Photo © Des Moines Register; used by permission

The environmental calculus is hardly better on the ethanol production side. Many U.S. ethanol refineries are powered by coal, hardly the most environmentally-friendly option. These facilities also emit large amounts of air pollutants that contribute to cancer, asthma and respiratory infections. By many estimates, current ethanol production systems may actually emit more greenhouse gases than gasoline. And a recent National Research Council report found that producing corn ethanol uses significantly more water than making gasoline.

The environment has not been the only loser. Anti-hunger groups point out that grocery bills have risen as growers divert two out of every five bushels of corn to ethanol production. For the last 33 years, taxpayers have subsidized oil and gas companies to blend ethanol with gasoline to the tune of as much as $6 billion a year.

With the possibility of E15 being sold soon, owners of small engines and older vehicles could also be on the losing end if their leaf leaf blowers, lawnmowers, outboard motors or chainsaws are damaged or need replacement. [Read more...]

Don't buy the industry's self-serving pronouncements. Corn ethanol is not an environmentally positive solution to our energy independence needs.

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3. McMahon, Kate and Victoria Wittig. “Corn Ethanol and Climate Change.” Accessed 20 October 2011 at






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