By Gene Ayres, Your Consumer Curmudgeon

Last year I posted a dispatch that included a note that warming up your car in winter is not a good idea. I know this sounds counterintuitive, but it really makes a lot of sense. And since this misunderstood and overused practice has not abated in the interim (in fact it should not be done at all), the onset of winter once more warrants a reprisal.

The other day I was out with my wife enjoying our mild Seattle winter weather (the sun was actually shining and it was in the high 40s) when I noticed a neighbor—a young woman, as it happened—come out of her unit, walk to her car in the parking lot, start it up, and go back inside. I suppose her thinking was that she'd have a nice warm and cozy car to blow hot air up her skirt when she was good and ready to drive off to work or go shopping, or whatever. This is just the sort of thoughtlessness that has gotten the whole world in a heap of trouble the last century or so, especially the last decade or so of our “me first” and the heck with the rest of the world mindset.

For starters, there is the simple fact of pollution. To put it simply, car engines that are warming produce double the exhaust pollution of cars already on the road. According to one recent study from the UK, more than 2,150 tons of C02 are generated from cars warming up daily in that country alone. You multiply that by five for the population difference and that's more than 10,000 tons per day in the USA of unnecessary C02 added to our atmosphere.

And how much gas is wasted in this process? Well, for starters, you're talking about zero miles per gallon, compared to your usual rate. And that costs you personally, literally, every time you leave your engine running while going nowhere, not to mention putting an added burden on our already limited global supply of fossil (or any other kind of) fuel.

Here are some idling myths courtesy of the Consumer Energy Center:

Idling Myths

Myth #1: The engine should be warmed up several minutes before driving.
Reality: Idling is not an effective way to warm up your vehicle. The best way is to simply drive, while avoiding rapid acceleration and high speeds for 3-5 miles. Today’s engines need to idle only 30 seconds prior to driving—even in winter.

Myth #2: Idling is good for your engine.
Reality: Excessive idling can actually damage your engine components, including cylinders, spark plugs and exhaust systems. Fuel is only partially combusted when idling because the engine does not operate at peak temperature. This leads to the buildup of fuel residues on cylinder walls that can damage engine components and lower mileage.

Myth #3: Shutting down and restarting your car is hard on the engine, and uses more gas than if you leave it running.
Reality: Frequent restarting has little impact on your battery and the starter motor. Component wear caused by restarting the engine is estimated to add $10 per year to the cost of driving, money that will be recovered several times over in fuel savings from reduced idling. The bottom line: more than ten seconds of idling uses more fuel than restarting the engine.

More 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 to about 7/10 (0.7) of a gallon for an 8-cylinder engine. Keep in mind that every gallon of gas you use produces about 19 pounds of carbon dioxide.

Excessive 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 on the town.

As to my neighbor, here's another sobering fact: were she (being of child-bearing age) pregnant, by leaving her car running and generating additional unnecessary pollution she is actually putting her fetus at additional risk before it is even born. A recent study from the Plosone Foundation found that air pollution can actually reprogram DNA in a developing fetus to make it much more susceptible to developing asthma later in life.

So please. Go out and turn off your engine until you're ready to go. You'll also increase the life of your transmission and differential, because a warm engine overloading a cold differential can be fatal to the car.

Put that in your coffee and stir it.

Sources: http://ecochildsplay.com/2009/01/12/lower-your-carbon-footprint-by-not-warming-up-your-car-this-winter/

http://www.sustainablehastings.org/uploads/Idlingbackmyths.pdf

http://www.plosone.org/home.action

Gene Ayres is a career writer, author and freelance journalist. His latest book is A Billion to One: An American Insider in the New China. He can be found at: www.geneayres.org.