FTC Consumer Alert

Federal Trade Commission Bureau of Consumer Protection Office of Consumer & Business Education

Good, Better, Best: 

How to Improve Gas Mileage 

Whether you are shopping for a new car or just trying to maintain the one you have, you can take 

some steps to get the best mileage out of your gas purchases. The Federal Trade Commission (FTC), 

the nation’s consumer protection agency, offers these tips to use fuel efficiently:

On the Road: Drive More Efficiently

•	 Stay within posted speed limits. Gas mileage decreases rapidly at speeds above 60 miles per 

hour. 

•	 Stop aggressive driving. You can improve your gas mileage up to five percent around town if 

you avoid “jackrabbit” starts and stops by anticipating traffic conditions and driving gently.

•	 Avoid unnecessary idling. It wastes fuel, costs you money, and pollutes the air. Turn off the 

engine if you anticipate a wait. 

•	 Combine errands. Several short trips taken from a cold start can use twice as much fuel as one 

trip covering the same distance when the engine is warm. 

•	 Use overdrive gears and cruise control when appropriate. They improve the fuel economy of 

your car when you’re driving on a highway. 

•	 Remove excess weight from the trunk. An extra 100 pounds in the trunk can reduce a typical 

car’s fuel economy by up to two percent. 

•	 Avoid packing items on top of your car. A loaded roof rack or carrier creates wind resistance 

and can decrease fuel economy by five percent.

At the Garage: Maintain Your Car

•	 Keep your engine tuned. Tuning your engine according to your owner’s manual can increase 

gas mileage by an average of four percent. Increases vary depending on a car’s condition.

•	 Keep your tires properly inflated and aligned. It can increase gas mileage up to three percent. 

•	 Change your oil. According to the U.S. Department of Energy (DOE) and Environmental 

Protection Agency (EPA), you can improve your gas mileage by using the manufacturer’s 

recommended grade of motor oil. Motor oil that says “Energy Conserving” on the 

performance symbol of the American Petroleum Institute contains friction-reducing additives 

that can improve fuel economy.
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September 2005

At the Pump: Use the Octane Level You Need

•	 Your owner’s manual recommends the most effective octane level for your car. For most cars,

the recommended gasoline is regular octane. In most cases, using a higher octane gas than the 

manufacturer recommends offers no benefit. Unless your engine is knocking, buying higher 

octane gasoline is a waste of money. 

In Advertising: Check Out Claims About “Gas-Saving” Gadgets

•	 Be skeptical of claims for devices that will “boost your mileage by an extra 6 miles per

gallon,” “improve your fuel economy up to 26 percent,” or the like. EPA has tested over 

100 supposed gas-saving devices — including mixture “enhancers” and fuel line magnets — 

and found that very few provide any fuel economy benefits. The devices that work provide 

only marginal improvements. Some “gas-saving” devices may damage a car’s engine or 

increase exhaust emissions. For more information and a full list of tested products, check 

www.epa.gov/otaq/consumer/reports.htm.

In the Showroom: Consider the Alternatives

•	 Alternative Fuel Vehicles (AFVs) operate on alternative fuels, such as methanol, ethanol, 

compressed natural gas, liquefied petroleum gas, electricity, and others designated by the 

DOE. Using these alternative fuels in vehicles may reduce harmful pollutants and exhaust 

emissions. FTC Rules require labels on all new AFVs to give the vehicle’s estimated cruising 

range and general descriptive information. Find out how many miles a new AFV travels on a 

tank or supply of fuel because, gallon for gallon, some don’t travel as far as gasoline-powered 

vehicles. 

•	 Hybrid Electric Vehicles offer another option for car buyers. According to DOE and 

EPA, these vehicles combine the benefits of gasoline engines and electric motors and can 

be configured to achieve different objectives, such as improved fuel economy and increased 

power. 

For more information on alternative fuel vehicles, call the DOE’s toll-free National Alternative 

Fuels Hotline, 1-800-423-1DOE, or visit DOE’s website at www.eere.energy.gov and click on 

“alternative fuels” and “vehicle technologies.” More information about both hybrid-electric and 

alternative fuel vehicles is at www.fueleconomy.gov.

For more energy saving tips for cars, click here to visit the DOE's website.

The FTC works for the consumer to prevent fraudulent, deceptive, and unfair business practices 

in the marketplace and to provide information to help consumers spot, stop, and avoid them. To 

file a complaint or to get free information on consumer issues, visit ftc.gov or call toll-free, 

1-877-FTC-HELP (1-877-382-4357); TTY: 1-866-653-4261. The FTC enters Internet, telemarketing, 

identity theft, and other fraud-related complaints into Consumer Sentinel, a secure, online database 

available to hundreds of civil and criminal law enforcement agencies in the U.S. and abroad.