"The biggest winter energy myth: That you need to idle your car before driving."
The Washington Post's Wonkblog recently published that headline, which is being disputed by some Alaska auto shop owners who advise residents to warm up engines, albeit briefly, when temperatures dip significantly below freezing. Better yet, say employees with state and local governments, plug in your car for a few hours when the thermometer drops to 20 degrees or below.
"The worst thing is to just hop in your car and take off," said John Stoehner, owner and general manager of Alaska Spring and Performance, an automotive repair shop in Anchorage.
While most newer vehicles will start and run in temperatures below zero degrees, that doesn't mean they necessarily should, said Ralph Seekins, owner of Seekins Ford Lincoln in Fairbanks, a city where normal temperatures in January range from 2 degrees to minus 18.
"You'll wear your engine block out far more quickly," he said. "(There are) unintended consequences that people don't think about in the Lower 48."
Seekins agreed that an engine will heat up more quickly when a vehicle is driven slowly than when it's idling, as reported by Wonkblog, quoting the Environmental Protection Agency and the U.S. Department of Energy. He said, though, that doesn't stop the quiet wear and tear during travel; nor does it help with visibility through frost-covered windows.
Typically, when temperatures drop below zero, Seekins said, he will start his car and let it run for roughly seven minutes in the morning. At minus 40 degrees, he will start his car for a few minutes every four hours. But at 32 degrees, he said, he will just get in and drive.
"That's a warm spell," he said.
In Anchorage, it's against municipal code to idle an unattended vehicle for more than 20 minutes, regardless of the weather, though that doesn't apply to police cruisers, fire trucks, ambulances, public utility vehicles and municipal vehicles providing public transportation.
Kurt Adler, owner of A&A The Shop in Anchorage, suggested that at 20 degrees and below, Anchorage residents warm up their vehicles for five to 10 minutes to kick-start the defroster and heater -- what Seekins called "creature comforts." But Adler said it takes only two to three minutes for a vehicle to reach "optimal driving conditions."
"We get in our car and we turn on the wipers, the blower, the radio, and pretty soon our alternator is going from temperatures of 20 degrees to 250 degrees because it's starting to generate all of this electricity and trying to push it into your battery that's still at 20 degrees and doesn't hold a charge," Adler said. "You want a $300 to $400 alternator change?"
When it comes to idling, fuel consumption and emissions also factor in.
Steve Morris, deputy director of the Anchorage Department of Health and Human Services, said the municipality recommends Alaskans plug in block heaters for two hours before leaving in the morning, the crux of the department's Plug@20 program funded by the federal government to cut carbon monoxide emissions
"You might use 15 cents of electricity during that time," Morris said. "But you can cut your idle time from seven minutes to three minutes."
According to a 2001 study by Sierra Research Inc. prepared for the Alaska Department of Environmental Conservation, a car in temperatures between 20 degrees and minus 20 emits 59 percent less carbon monoxide when plugged in for two hours and idled for 10 minutes.
The study also identified 10 minutes as the "optimum" idle period. A car idled for 10 minutes and then driven dispenses less carbon monoxide overall than if just driven cold, it said.
Wonkblog, citing a 2009 study in Energy Policy, reports that all vehicle idling, including idling in traffic, contributed to 1.6 percent of U.S. greenhouse gas emissions.