It was always a habit of mine to warm up and idle the car in the morning to avoid engine damage.  Yet, I was surprised to find out that enforcing this daily rigorous step would do more harm than good, not only to the car, but also to the environment.  You don’t need to idle the car, because of the efficiency of modern fuel injection, which eliminated carburetors and chokes.  The only reason to let the car idle at all is to get the oil circulating for 30 seconds.

Quick facts and tips that should put the idling question to rest: [1]

1. Driving warms the car faster than idling

If your concern is not the health of the car, but simply your comfort to stay warm, Bob Aldrich of the California Energy Commission points out that “idling is not actually an effective way to warm up a car – it warms up faster if you just drive it.”

The coming of electric cars will incorporate a wonderful feature that allows the owner to use a cellphone to tell the car (which is plugged into the grid) to pre-warm or pre-cool the interior.  No idling necessary.

2.  Ten seconds is all you need

Environmental Defense Fund, which produced the Idling Gets You Nowhere campaign, advises motorists to turn off their ignition if they’re sitting stopped for more than 10 seconds.

“After about 10 seconds, you waste more money running the engine than restarting it, said Andy Darrell, deputy director of the EDF Energy Program.  “Switch the car off and you’ll be leaving money in your wallet and protecting the air in your community.”

3. Idling hurts the car

According to the Hinkle Charitable Foundation’s Anti-Idling Primer, idling forces an engine “to operate in a very inefficient and gasoline-rich mode that, over time, can degrade the engine’s performance and reduce mileage.

The Campaign for an Idle-Free New York City points out that idling causes carbon residues to build up inside the engine, which reduces its efficiency.

4. Idling cost money

Over a year of five minutes of daily idling (which causes incomplete combustion of fuel), the “Anti-Idling Primer” estimates that the operator of a V8-engine car will waste 20 gallons of gasoline, which not only produces 440 pounds of carbon dioxide but costs at least $80.

5. Idling in the garage can kill you.

Idling a car in a garage, even with the door open, is dangerous and exposes the driver to carbon monoxide and other noxious gases.  If the garage is attached, those fumes can also enter the house.

6. Quick errands aren’t quick enough

Natural Resources Canada points out that leaving your car idling while you’re running into a store on an errand or going back into the house to pick up a forgotten item is another way to waste gas and pollute both your town and the planet.

“Leaving your engine running is hard on your pocketbook, produces greenhouse gas emissions, and is an invitation to car thieves,” the agency says.

7. Idling is bad for your health (and your neighbor’s health)

According to Minneapolis’ anti-idling ordinance, “Exhaust is hazardous to human health, especially children’s;  studies have linked air pollution to increased rates of cancer,  heart and lung disease, asthma and allergies.”

Isabelle Silveman, who runs EDF’s anti-idling campaign, says that car idling “is the second-hand smoking of the outdoors.  One of the problems is that cars idle close to the curb, where pedestrians are walking.  And when you have a child in a stroller, they are particularly close to the tailpipe.  Studies show that children’s IQ levels are lower when they live near major roads with lots of traffic.” (A fresh study even links autism to freeway pollution.)