NEWS: GM's warm-up advice stirs up controversy

Read ecoDriver Manitoba's response to this story.

January 2, 2010
Winnipeg Free Press

General advises idling before driving: experts, activists hotly disagree

MILWAUKEE -- Three things you don't discuss over the dinner table: religion, politics, and how long a car should warm up before driving in the cold.

As the temperature drops, more people are letting their cars run a while before hitting the road.

Earlier this month, General Motors issued a news release recommending that motorists warm their engines before driving as a way to reduce engine pollutants.

"While this may seem counterintuitive, a warm engine emits significantly fewer unburned hydrocarbons during the first accelerations," GM said in the release promoting its remote starters for cars, sport utility vehicles and pickups.

"That's because the catalyst that traps the unburned hydrocarbons only activates once the engine is warm," the automaker notes.

Not everyone agrees that letting a car idle in the driveway is a good practice, even on a cold day.

Idling will not help emission control systems reach operating temperatures, according to the U.S.Environmental Protection Agency.

"Modern vehicles need little warm-up. Idling for long periods in cold weather can actually cause excessive engine wear," the EPA notes in a report.

Madison and some other Wisconsin municipalities have anti-idling ordinances aimed at reducing greenhouse gases.

In some Canadian cities, including Toronto, it's illegal to allow a passenger vehicle to idle for more than three minutes.

Idling is a source of pollution that governments are looking to reduce because of airborne particulates and smog, said Jennifer Feyerherm, director of the Sierra Club's Wisconsin Clean Energy Campaign.

"Cars run more efficiently when they are being driven rather than idling," Feyerherm said.

Technically you can get in your vehicle and drive without a warm-up even on the coldest day. The electronic fuel systems and lubricants in newer cars can handle low temperatures, said Ken Kempfer, an automotive technology instructor at Fox Valley Technical College.

A car will warm up quicker when it's driven, said Joe Bruzek, an editor at Cars.com, a website for car enthusiasts.

Drive gently the first few minutes in the cold, but a minute or two is enough of a warm-up, according to Bruzek.

"Letting your car idle in the driveway for 10 minutes is more about getting into a warm, toasty vehicle after drinking your coffee in the living room," he said.

A car driven in 14-degree weather for 12 minutes will reach the same operating temperature as one that idles for 30 minutes, according to a study by the Ontario Ministry of Transportation.

Yet there are merits to running your car's engine some before driving in the bitter cold -- especially if it helps clear frost off the windows.

"I would want to warm up my car a little bit before I put my baby in it," Feyerherm said.

A car's lubricants and fluids are sluggish in the cold, said Gary Klopp, director of automotive services for AAA-Minnesota.

"Let the car come to its senses, so to speak, before you put it in gear," he said. "That's going to be much better on most of the mechanical components."

Klopp said he can tell by the sound of his car when it's ready to go.

He has learned to listen to the creaks, groans and other noises associated with a cold engine and transmission.

"When you start your car in extremely cold weather, there's high oil pressure, friction and other things going on. Everything in the engine is trying to find its mechanical mate and jive," Klopp said. "To just start the engine and take off, I think, is abusing the car. At some point it's going to result in premature wear."

-- Milwaukee Journal Sentinel

 

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