Questions & Answers

Renewable Fuel Standard 

Implementation: Frequently Asked 

Consumer Questions

EPA420-F-07-062

November 2007

Office of Transportation and Air Quality

The U.S. Environmental Protection Agency has prepared this document to help answer some commonly asked questions about renewable fuels. EPA consulted with trade groups representing the oil, engine, 

automobile, and renewable fuels industries as well as the U.S. Department of Energy to prepare these responses.

What are renewable fuels?

They are fuels produced from plant or animal products or wastes, rather than from 

fossil fuels. The best known renewable fuels today are ethanol and biodiesel.

Ethanol has been added to gasoline for more than a decade in Chicago and Milwaukee. For the last several years, ethanol has also been blended with gasoline in many 

metropolitan areas across the country. About half of the gasoline used today in the 

United States is blended with ethanol at levels of up to 10% by volume (this is 

called “E10”). Ethanol blends at higher volumes, such as 85% (“E85”), are available 

in some areas for use in specially designed “flexible-fuel vehicles.” Biodiesel has been 

used most widely in Minnesota, and can now be found in many other states.

Why is EPA requiring the use of renewable fuels?

Congress directed EPA in the Energy Policy Act of 2005 to design a program that 

requires the blending of renewable fuels into our nation’s motor-vehicle fuel supply. 

This program is called the Renewable Fuel Standard. 

The RFS program requires increasing the use of renewable fuels every year through 

2012. For 2007, a minimum of 4% of fuel dispensed to U.S. motorists shall come 

from renewable sources (a floor of 4.7 billion gallons). By 2012, at least 7.5 billion 

gallons of renewable fuel must be blended into motor-vehicle fuel sold in America. 

After 2012, renewable fuel use is required to grow in volume as gasoline demand 

grows.
Questions & Answers

Renewable Fuel Standard Implementation 

In 2006, American refiners, blenders, and importers used 5.4 billion gallons of renewable fuel 

—almost 25% more than was required for that year.

Will renewable fuel be more expensive than conventional fuel?

No one can predict with certainty the price of fuel at the pump. Many factors affect the sales 

price including production costs, crude oil’s price, taxes, inventory levels, and supply and demand. Geopolitical factors, weather, transportation, and economic events also can affect the 

sales price. Visit the Energy Information Administration for more information on fuel prices.

EPA estimates the cost to produce a gallon of ethanol-blended gasoline will rise between 0.5 and 

1.1 cents. However, because ethanol receives a tax credit, EPA estimates consumers might actually see a net savings at the pump of 0.4 to 0.7 cents per gallon.

Are renewable fuels compatible with my car or truck? How about my 

lawnmower or boat?

Manufacturers expect ethanol blends of up to 10% to be fully compatible with current and 

previously manufactured gasoline-powered vehicles and engines. However, certain components 

of older vehicles or engines that are operated in areas where ethanol is new might be affected. 

As part of a good maintenance program and to alleviate any potential complications, owners are 

encouraged to monitor their vehicles or engines for hose, seal, or gasket leaks. 

Consult your owner’s manual or servicing dealer for any special instructions. Manufacturers 

might offer specific recommendations for preparing lawnmowers, boats, and other products for 

storage during the off-season.

Owners of boats with older fiberglass tanks are urged to consult their servicing dealer before using ethanol blends.

Biodiesel’s compatibility with vehicles and engines depends on the amount of biodiesel in the 

diesel fuel blend as well as the specific vehicle or engine. Most diesel-powered vehicles and 

engines are compatible with a level of up to 5% biodiesel, while some vehicles and engines are 

compatible with a higher percentage. Consumers should check their owner’s manual or consult 

with the manufacturer for fuel recommendations and warranties.

How will renewable fuel affect the performance and fuel economy of 

my car, truck, lawnmower, or boat?

Under typical operating conditions, there should be no noticeable impact on overall power or 

performance when using 10% ethanol blends. As discussed above, certain components of older 

engines that are operated in areas where ethanol is new might be affected, and a good maintenance program is recommended. Fuel economy will be reduced slightly with ethanol blends 

because ethanol has about two-thirds of the energy content of gasoline.
Questions & Answers

Renewable Fuel Standard Implementation 

Will using renewable fuels void my vehicle or engine warranty?

Consumers should check their owner’s manual or consult with the manufacturer to identify 

which fuels are recommended or allowed, and then check the fuel pump label to ensure they are 

using fuel consistent with manufacturer recommendations. In general, most vehicle and engine 

manufacturers recommend or accept the use of ethanol in fuel blends at volumes of up to 10% 

for gasoline-powered vehicles and engines. Owners of flexible-fuel vehicles may use ethanol 

blends at volumes of up to 85%. Most manufacturers accept biodiesel blends at levels of up to 

5% for use in diesel-powered vehicles and engines. 

How will renewable fuel affect air quality?

EPA estimates that the RFS program will cut petroleum use by up to 3.9 billion gallons and 

greenhouse-gas emissions by up to 13.1 million metric tons annually by 2012—the equivalent of 

eliminating the greenhouse-gas emissions of 2.3 million cars.

In areas that haven’t previously used ethanol, small increases in ambient ozone formation might 

be expected. Carbon monoxide and benzene emissions will be reduced.

Will renewable fuel differ in smell or appearance?

The addition of renewable fuel to gasoline or diesel fuel might affect the appearance or odor of 

the fuel, but it should not affect its quality or performance.

Are all refiners required to produce renewable fuel blends?

Most refiners, blenders, and importers are required to use a minimum volume of renewable fuel 

each year beginning Sept. 1, 2007, and each year thereafter. Alternatively, they must buy credits 

from other companies that choose to use more than their required minimum volume. That minimum volume is determined as a percentage of the total volume of motor-vehicle fuel a company 

produces or imports, and will increase every year.

Small refiners are exempt through 2010. All gasoline producers in Alaska and U.S. territories 

are exempt indefinitely. Hawaii, previously granted an exemption, is opting into the program 

effective Jan. 1, 2008.

Where can I purchase renewable fuel blends?

EPA does not require service stations or truck stops to sell renewable fuel blends. Therefore, it 

is possible that a particular renewable fuel blend won’t be available in some areas. If you have 

questions about renewable fuel content or availability, ask your local retailer.
Questions & Answers

Renewable Fuel Standard Implementation 

How will I know which pump is dispensing renewable fuel blends?

EPA does not require service stations or truck stops to label the pumps that dispense renewable fuel blends. Some states, however, require that pumps dispensing renewable fuel blends be 

labeled.

May I continue to purchase fuel without a renewable component if I 

prefer to use it in my vehicle, lawnmower, or boat?

EPA does not require consumers to purchase renewable fuel blends. Some states mandate the use 

of renewable fuels, so fuel without a renewable component might not be available in some areas.

How can I get more information?

You can access documents on renewable fuels at www.epa.gov/otaq/renewablefuels

For more information on the Renewable Fuel Standard, please contact Deborah Wood at 

wood.deborah@epa.gov, 202-343-9249, or:

Deborah Wood

Office of Transportation and Air Quality 

U.S. Environmental Protection Agency

Mailcode 6406J

1200 Pennsylvania Ave., NW

Washington, DC 20460