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Be Idle Free

Idling your vehicle gets you nowhere. It increases our dependence on petroleum, reduces the fuel economy of your vehicle, costs you money, emits pollutants, and wastes precious natural resources. Researchers estimate that idling from heavy-duty and light-duty vehicles waste about 6 billion gallons of fuel annually. When you make an effort to turn your vehicle off, you are doing something good for yourself, your finances, your environment, and your community.

Modern Cars Don’t Need to Idle

Advances in vehicle technology have eliminated much of the need for idling, making it easier than ever to avoid unnecessary idling. Computerized controls in today’s vehicles bring the engine and catalyst up to their operating temperatures more quickly when the vehicle is moving than when it is idling. The catalytic converter that reduces emissions also operates much sooner if the car is driven right away rather than idled. Even on the coldest day, it takes a modern vehicle less than 5 minutes to warm the engine if the car is moving.

In contrast, it takes the engine almost twice as long to warm up if the car is merely idling. In moderate weather, the catalytic converter can even maintain its operating temperature and immediately resume emissions reduction if the driver restarts the car for up to 30 minutes after he or she turns off the ignition. Similarly, today’s gasoline and diesel vehicles alike do not suffer damage from turning the key on and off. Starters and batteries are much more durable than people believed they were in the past. In fact, today’s owner’s manuals, which usually contain information on how to get the best and most economical fuel and engine performance, generally do not recommend idling.

Consider Your Circumstances

Most idling can be avoided. If the line at the drive-through restaurant or bank is long, consider turning off your car while you wait. You can also park and go into the building. When waiting for passengers, consider the weather. If the temperature is moderate, it is a good idea to turn off the engine. This is especially important while waiting to pick up schoolchildren because parents’ idling vehicles can impact air quality. Since children’s lungs are more susceptible to damage than adult’s lungs, unnecessary idling around schools can exacerbate childhood asthma and other respiratory ailments.

There are a few circumstances where idling is unavoidable. You must keep your car running for safety reasons when waiting in traffic jams. When it is time for emissions testing of your vehicle, your inspection station may require you to idle so that your engine is up to its operating temperature.

Solutions Exist

For consumers, the best technology to reduce idling—beyond individual actions—is driving a hybrid vehicle. A hybrid shuts off the engine when stationary so there are no emissions from the tailpipe while waiting in traffic or drive-throughs. As hybrid vehicles gain a larger market share, it is likely that fewer vehicles on the road would idle unnecessarily.

Idling problems extend beyond consumer vehicles. Reducing idling in a number of community vehicles, such as police cruisers, school buses, taxis, ambulances, and government fleets, can bring even bigger benefits. While emergency vehicles (ambulances, police cars, and fire engines) are usually exempt from anti-idling regulations, there is equipment that can be added to these vehicles to prevent idling while providing power and comfort. Ambulances can plug in at hospitals to keep equipment running, police cars can use automatic start-stop devices or supplementary power sources, and school buses can use block heaters to warm the engines to operating temperatures in the morning.

School Buses Offer Unique Opportunities

As parents are often concerned about the poor air quality around their children’s school, many anti-idling campaigns have targeted diesel-powered school buses. School districts nationwide have responded to these campaigns by passing regulations and training drivers on idle reduction techniques. In a landmark effort that has become a model for other states, the Utah State Office of Education, in partnership with the Utah Clean Cities Coalition, developed a state school bus idle reduction program. Almost 3,000 bus drivers in 40 school districts reduced their idle time by an average of 21 minutes per day.

Education and metrics have been key components of the program’s success. The idle reduction program is part of the official curriculum for school bus drivers. Tracking measures helped build confidence in the program and were instrumental in charting progress, emission reductions, and cost savings. The U.S. Environmental Protection Agency’s Clean School Bus USA program has many links that can help parents and school districts reduce idling. In addition to improving air quality, reducing unnecessary idling can save school districts money through reduced fuel cost and engine wear.

Each Citizen Can Contribute

Once you have a better idea of why people idle, it’s easy to reduce your own idling and encourage smart, responsible behavior in your community.

  • Talk to the principal of your child’s school about posting anti-idling signs in areas that school buses and parents wait for pick-up and drop-off.
  • Work with your school board on a district-wide anti-idling campaign.
  • Talk to the manager of your bank, drive-through restaurant, or pharmacy about ways to reduce wait times in line as a way to reduce idling. Suggest that signs be posted to remind patrons not to idle while waiting.
  • Encourage your employer to implement anti-idling policies in the workplace.

Anti-Idle Calculators

  • Heavy Duty Vehicle Anti-Idle Calculator (234 KB)
  • Light Duty Vehicle Anti-Idle Calculator (368 KB)

Fact Sheet Information Courtesy of the U.S. Department of Energy Vehicle Technologies Program.

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