Winter weather can be particularly harsh on cars. During the cold months, people across the country sit in their idling cars, waiting on the engine to warm up. Many people believe that a car needs to run for about five minutes before they can take off on their morning commutes. It is a little-known fact, though, that idling your car on cold mornings can be harmful to your health.
Letting your engine warm up for minutes before driving on cold winter mornings has not always been a bad thing. In the 1980s, car manufacturers began installing modern fuel injection systems instead of carburetors. Carburetors needed time to reach the correct air-to-fuel ratio or you could risk stalling your car out. Since electronic fuel injection systems adjust air-to-fuel ratio based on readings from your car’s oxygen sensors, your car does not need to idle before you drive it on cold mornings.
If your car was built after 1990, it has a modern fuel injection system and does not need a long warm-up period. According to the U.S. Department of Energy, you do not need to warm up your car longer than 30 seconds before driving it on cold mornings. It wastes fuel and produces greenhouse gas emissions. The engine will warm up as you drive your car.
Idling your car on cold mornings does not only affect your car’s health, though. Leaving your car running for more than 30 seconds before driving it can have a negative impact on your health, as well. Idling for more than 10 seconds emits significant amounts of carbon dioxide, causing an increased amount of air pollution. The harmful chemicals in your car exhaust can exacerbate asthma and promote allergic reactions and airway constriction.
People with asthma should be especially careful when warming up their cars on cold winter mornings. Cars emit particles that can penetrate the lungs and cause respiratory inflammation, which can damage cells and worsen asthmatic symptoms.
Since asthmatics are vulnerable to air pollution, they should take precautions to avoid idling their cars on cold winter mornings, such as parking in a garage, combining trips and only using defrosters when necessary.