Should You Let Your Car Warm Up in Freezing Temperatures?

Most of us are under the assumption that we should let our cars “warm up” before we drive on extra cold days such as this. That may not be true! Read ahead for a few facts and myths about this very thing:

Old habits die hard, and one of the oldest-still rigorously enforced by many drivers-is that “warming up” the car for a few minutes is necessary to avoid some kind of unspecified damage.

A mechanic states: “You don’t really need to idle your 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, but after 30 seconds that’s a done deal. My truck has 150,000 miles on it, and I just throw it into gear and go.”

Here are some quick facts and tips that should put the idling question to rest:

Driving Warms the Car Faster than Idling
If your concern is not the health of the car, but simply your own creature comforts, 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 electric cars, such as the Nissan Leaf, 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. 

Ten Seconds Is All You Need
Environmental Defense Fund advises motorists to turn off their ignition if they’re sitting stopped for more than 10 seconds. “After about ten 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 at the curb and you’ll be leaving money in your wallet and protecting the air in your community.”

Idling Hurts the Car
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.”

Idling Costs Money
Over a year of five minutes of daily idling (which causes incomplete combustion of fuel), it is estimated that the operator of a V-8-engined car will waste 20 gallons of gasoline, which not only produces 440 pounds of carbon dioxide but costs at least $60. 

Idling in the Garage Can Make You Sick or Worse 
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.

Block Heaters Beat Remote Starters
Remote starters can too easily cause people to warm up their cars for five to 15 minutes, which is generally unnecessary. A block heater, which is designed to heat the engine and can cost under $30, on a timer set to start one to two hours before driving does the trick in very cold climates.