Cleaning the Air Campaign (Anti-Idling)

You can easily reduce pollution and carbon dioxide emissions by NOT idling your car when parked. In fact, idling for more than five minutes unnecessarily is illegal! (Massachusetts General Laws, Chapter 90, section 16A.) Sustainable Belmont is working to communicate to community members the importance of not idling and to dispel myths about idling.

Idling Myths and Facts for Cars

Fact: Idling Gets Us Nowhere

Myth: The engine should be warmed up before driving.

  • Idling is not an effective way to warm up a vehicle – driving is.
  • An engine is sufficiently warm after 30 seconds, even in winter.

Myth: Idling is good for your engine.

  • Engines are designed to drive, not idle.
  • Excessive idling can damage engine components including cylinders, spark plugs, and the exhaust system.
  • Your engine is not working at peak operating temperature when it’s idling, so fuel does not go through complete combustion.
  • Idling allows water to condense in the exhaust system causing corrosion and can reduce the life of the exhaust system.

Myth: Shutting off and restarting is hard on your engine and uses more fuel.

  • More than 10 seconds of idling uses more fuel than restarting the engine.
  • Frequent restarting has little impact on engine components

Myth: Idling for a few minutes doesn’t matter.

  • Idling wastes fuel and money. Idling five minutes here and there throughout the day can add up to more than a gallon of fuel wasted in a day.
  • Burning gasoline contributes to climate change gases. Every gallon of gas produces about 20 pounds of carbon dioxide when combusted.
  • Vehicle idling contributes to air pollution in the local and community level.
  • If you’re going to be parked for more than 10 seconds, turn off your engine

Myth: I need to keep my car running to keep it warmed up in the winter.

  • Cars only need 30 seconds of idling on a cold day before driving. Today’s modern engines warm up more quickly once a car is operating.

Why do we idle?

  • Waiting for passengers
  • In drive-through lanes at fast-food restaurants or banks
  • Running quick errands
  • Stopping to talk to an acquaintance or friend
  • Preparing to leave the house
  • Listening to the end of a song or story on the radio

What should you do?

  1. TURN IT OFF. Turn off the engine if the vehicle is going to be parked for more than 10 seconds (except in traffic).
  2. DRIVE. Drive your vehicle to warm it up rather than idling (no more than 30 seconds is needed on winter days to circulate the oil through the engine).
  3. GET A TUNE UP. A poorly maintained car can release as much as 100 times the pollution of a well maintained car.
  4. TRIP CHAIN. Combine multiple trips into one outing.
  5. SPREAD THE WORD. Tell a friend about how to save money, reduce pollution, and not idle.

Sustainable Belmont members work with the Town of Belmont’s public works and police departments and the Belmont Public Schools on the Cleaning the Air Campaign. We have also joined community groups to cosponsor Walk to School Days. For more information or to join the Cleaning the Air Campaign Working Group, please contact The Belmont Police Department also supports an Anti-Idling Program (

To learn more about Sustainable Belmont’s Cleaning the Air Campaign, see the following articles:

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Our campaign materials may be downloaded below.