Why Warming Up the Car is the Worst Thing You Can Do This Winter

Depending on where you live, the Winter season is either right around the corner, or has already dumped 36 inches of fluffy white love in your lap (our Colorado town is of the latter variety).

This means that soon it will be necessary for many walkers and bikers to start using their cars again, and many will participate in the winter tradition of “warming up the car.” Although this excessive idling is considered a necessary and sometimes chivalrous act, it contributes to a dramatic increase in air pollution during the cold weather season.

In fact, “in winter conditions, emissions from an idling vehicle are more than double the normal level immediately after a cold start (Hamilton County).

Many people are unaware that heating up the car can have such harmful effects, and we are all confused by myths like “it takes more gas to turn the car on than to keep it running, or “turning the car on and off damages the engine.” So we sit and wait for the frost to dissolve on the windsheild and the seat warmers to be cranking at full capacity before we climb in.

Although typically ignored or played down by state and even national environmental regulators, more people need to be educated that the best way to warm up your car or truck is to drive it. And studies have shown that frequent restarting has little impact on engine parts such as battery and starter motor.

Idle Facts:

  • Ten seconds of idling can use more fuel than turning off the engine and restarting it. If you are stopped for more than 10 seconds – except in traffic – turn off your engine.
  • Every 10 minutes of idling costs you at least 2/10 (0.2) of a gallon of gas – and up about 7/10 (0.7) of a gallon for an 8-cylinder engine. Keep in mind that every gallon of gas you use you produce about 19 pounds of carbon dioxide.
  • Exessive idling occurs at drive through windows, drive through bank deposits, and train crossings; while waiting for your kids to get out of school, running into the convenience store, and when picking up your friends for a night out.

To make matters worse, research published in PLoS ONE Journal suggests that “pollution from traffic can ‘reprogram’ genes in the womb, increasing the risk for asthma.” Even if you don’t buy the studies findings that fetuses breathing in exhaust will have asthma, doctors are already sure that “pollution triggers symptoms in two thirds of people with asthma, and many say that a reduction in air pollution would make the single biggest difference to their quality of life.”

A good rule of thumb is: “Idling gets zero miles per gallon.”

In the United States and Canada, if every driver avoided idling for just 5 minutes a day, millions of tons of CO2 would be prevented from entering the atmosphere each year. That would represent a staggering contribution to positive climate change efforts (Gary Klinga).

TAKE ACTION by signing one of these Care2 petitions, and remember that a pair of gloves, a handy windshield scraper and a few minutes of cold are small sacrifices for a healthy planet.

Clean Air for Children

Ban Drive-Thrus in Canada

Image Credit: blog.lehighvalleylive.com


William C
William C10 days ago

Thank you.

W. C
W. C10 days ago

Thanks for the article.

Pablo B.
.2 years ago


Florence Baribeau

I live in the North, If I don't warm up my car during the winter, that'll ruin my car. You cannot just start and go! If I don't warm it up, I cannot see through the windshields I can't change the gear their too cold.

I warm it enough for the windshields are safe to see through, it's the only way. Horses and buggies should come back just like the Mennonites and other cultures that still uses horses, then it'll be safer for all!!!

Helga Ganguly
Helga Ganguly2 years ago

I hate idling. I hate idling in California by people on cellphones waiting to finish a call.I now live in a colder clime.I won't drive unless the weather is not icy.Fewer trips,less carbon. And do I really need a can of whipped cream?

Dan Blossfeld
Dan Blossfeld2 years ago

The facts are a little off. That should read 2/10 of a litre, not gallon. A V8 engine will use that amount of gas at top speed every 10 minutes, and it has to move the vehicle. While starting and stopping the car will not damage the engine (maybe the starter), running the car cold can cause more damage than a warm vehicle. Lubrication is much poorer at cold temperature, generating much higher friction. Safety issues come into play, when the windows are iced over, such that defrosting (while idling) makes for good practice. Not everything is about emissions.

Carole R.
Carole R2 years ago

Good to know.

dana h.
dana h2 years ago

I may have to compromise

LMj Sunshine
James Merit4 years ago

Thank you for info.

LMj Sunshine
James Merit4 years ago

Thank you for info.