The thickest winter energy myth: That you need to idle your car before driving

The inwards track on Washington politics.

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AP Photo/Hazleton Standard-Speaker Ellen F. O’Connell

We’ve all heard the idea: In winter, your car needs a little time to warm up before you can drive it. And that’s why across the United States, people who live in cold and snowy places — and especially those whose cars have remote starters — often fire up their engines long before they commence driving. Heck, they might even begin the car from the kitchen in the morning, and only then embark the coffee brewing.

But it turns out that this idea of idling your car during the winter is just wrong. And so are the many, many Americans who believe it — one two thousand nine examine found that on average, Americans thought they should idle for over five minutes before driving when temperatures were below thirty two degrees!

Like many misconceptions, the idea behind winter car idling starts with a kernel of truth. Cars do get worse fuel economy when it’s truly cold out — they are at least twelve percent less fuel efficient, according to Environmental Protection Agency and Energy Department. And it does take longer for the engine to warm up and reach an optimal driving temperature in cold weather.

Moreover, older cars — which relied on carburetors as a crucial engine component — did need to warm up to work well, according to several auto industry experts. Without heating up, the carburetor would not necessarily be able to get the right mix of air and fuel in the engine — and the car might stall out. During the 1980s and into the early 1990s, however, the auto industry did away with carburetors in favor of electronic fuel injection, which uses sensors to supply fuel to the engine and get the right air and fuel mix. This makes the problem of heating up the car before driving irrelevant, because the sensors monitor and adjust to temperature conditions.

Idling in winter thus has no benefit to your (presumably modern) car. Auto experts today say that you should warm up the car no more than thirty seconds before you begin driving in winter. “The engine will warm up swifter being driven,” the EPA and DOE explain. Indeed, it is better to turn your engine off and begin it again than to leave it idling. (As many readers pointed out after this post was very first published, it’s always significant to be careful driving in winter, and clear your windshield of any ice.)

So idling does nothing for your vehicle, but it does have several big (and avoidable) costs: Wasting fuel, and providing off greenhouse gas emissions and other types of pollution.

To display as much, Natural Resources Canada — the energy and resources agency of a cold country that also has serious idling problems — ran an idling experiment, freezing three cars to minus eighteen degrees Celsius and then driving each one the same distance. Sometimes the cars were idled five minutes before driving, and sometimes ten minutes. The result was that the more idling time, the more wasted fuel.

“The test results displayed that with a 5-minute warm-up total fuel consumption enhanced by seven to fourteen percent and with a 10-minute warm-up total fuel consumption enhanced by twelve to nineteen percent,” the agency reported.

The Department of Energy’s Argonne National Laboratory, which has also conducted much research on idling, reported that “idling fuel consumption is, of course, linear with time, and increases with engine size”:

Or to put it more bluntly: Whereas newer cars are permanently improving the miles they get per gallon driven, idling will always be stuck in place — using up gas, but getting no miles for it.

But it’s not just fuel waste, it’s the accompanying emissions. What does it look like when you have a entire population of people — or at least the northern belt of a country like the U.S. — idling their cars in winter?

A two thousand nine probe in Energy Policy attempted to calculate the consequences. The researchers found that, overall, all types of vehicle idling — idling in winter, idling while waiting for someone or something, and idling in traffic — contribute a staggering 1.6 percent of all U.S. greenhouse gas emissions.

That number is “almost dual the total emissions for the metal and steel manufacturing industry,” the paper noted. (In fairness, since the explore was published vehicle fuel economy has improved, and fresh vehicle greenhouse gas emissions have declined, thanks to fresh regulations. So especially for fresh vehicles, this may somewhat blunt the overall effects of idling.)

That is not to say that all idling should be stopped instantly. Some idling — particularly in traffic — may be unavoidable. But the other two categories of idling — in winter and while waiting — make a lot less sense. And the investigate found that they account for almost half of all U.S. greenhouse gas emissions attributable to idling.

And no wonder: When 1,300 Americans were surveyed about idling for the investigate, almost half reported both idling their cars for longer than thirty seconds to warm them up and idling for more than thirty seconds because of waiting. Indeed, the average amount of time that respondents thought you should idle your car before driving, when it is lower that thirty two degrees Fahrenheit outside, was Five.01 minutes! And since that’s the average, many people thought you should idle for a lot longer than that.

“These values indicate that beliefs about how much idling is adequate or desirable are very crooked,” the authors wrote.

The probe found that if people would just knock off unnecessary idling of this sort, then consumers as a entire would save $Five.9 billion per year on fuel costs (based on the cost of fuel in 2008). The saved emissions, the explore noted, would be “larger than the emissions from the soda ash, aluminum and limestone industries combined.”

Idling behavior, the paper concluded, is “worthy of policymakers’ attention.” Some have taken note. For example, often-freezing Minneapolis has an anti-idling statute that restricts all non-traffic idling to three minutes per hour (with some exceptions). Anti-idling laws across the country vary, but some localities go after a similar course. So idling isn’t just pointless — beyond a point, it may even trigger a hefty fine.

Meantime, technological advances, and the thrust for ever greater fuel economy, are even embarking to help deal with the most unavoidable type of idling: Idling because you’re stuck in traffic. Vehicle start-stop technology literally shuts down the engine when your car is stopped, and automatically switches it on again when you embark to drive again. This technology tends to be found in hybrids but has spread to other cars as well. GM now boasts that ninety seven percent of buyers of a two thousand fourteen or two thousand fifteen Chevy Malibu bought a car with start-stop technology.

So, it’s hard to see any redeeming value to idling your car in winter. For the final word on the dumbness of this practice, let’s turn to the late Tom Magliozzi, the never-to-be-forgotten co-host of NPR’s “Car Talk.” As he put it to a Boston listener named Lisa, who had asked about her beau’s conviction that you need to idle up to ten minutes in winter:

“Dear Lisa’s Bf: You have your head so far up your tailpipe on this one, it may be coming out your air intake.”

Update: Many readers have responded to this chunk by raising some good and interesting points. In particular, some folks have noted that they idle their cars in winter not for the sake of the engine, but rather for convenience (warmth) or because it helps in defrosting. While this article was focused solely on the energy and fuel consequences of idling, I acknowledge these other reasons. That said, the research cited above does suggest that many people think idling is necessary for their car’s engine, not for convenience or safety. So please, click the links if you have more questions about idling (here’s EPA and DOE, and here’s Argonne National Laboratory), and have a blessed and safe driving practice this winter!

The fattest winter energy myth: That you need to idle your car before driving – The Washington Post

The largest winter energy myth: That you need to idle your car before driving

The inwards track on Washington politics.

*Invalid email address

AP Photo/Hazleton Standard-Speaker Ellen F. O’Connell

We’ve all heard the idea: In winter, your car needs a little time to warm up before you can drive it. And that’s why across the United States, people who live in cold and snowy places — and especially those whose cars have remote starters — often fire up their engines long before they begin driving. Heck, they might even commence the car from the kitchen in the morning, and only then begin the coffee brewing.

But it turns out that this idea of idling your car during the winter is just wrong. And so are the many, many Americans who believe it — one two thousand nine examine found that on average, Americans thought they should idle for over five minutes before driving when temperatures were below thirty two degrees!

Like many misconceptions, the idea behind winter car idling embarks with a kernel of truth. Cars do get worse fuel economy when it’s truly cold out — they are at least twelve percent less fuel efficient, according to Environmental Protection Agency and Energy Department. And it does take longer for the engine to warm up and reach an optimal driving temperature in cold weather.

Moreover, older cars — which relied on carburetors as a crucial engine component — did need to warm up to work well, according to several auto industry experts. Without heating up, the carburetor would not necessarily be able to get the right mix of air and fuel in the engine — and the car might stall out. During the 1980s and into the early 1990s, however, the auto industry did away with carburetors in favor of electronic fuel injection, which uses sensors to supply fuel to the engine and get the right air and fuel mix. This makes the problem of heating up the car before driving irrelevant, because the sensors monitor and adjust to temperature conditions.

Idling in winter thus has no benefit to your (presumably modern) car. Auto experts today say that you should warm up the car no more than thirty seconds before you embark driving in winter. “The engine will warm up swifter being driven,” the EPA and DOE explain. Indeed, it is better to turn your engine off and begin it again than to leave it idling. (As many readers pointed out after this post was very first published, it’s always significant to be careful driving in winter, and clear your windshield of any ice.)

So idling does nothing for your vehicle, but it does have several big (and avoidable) costs: Wasting fuel, and providing off greenhouse gas emissions and other types of pollution.

To showcase as much, Natural Resources Canada — the energy and resources agency of a cold country that also has serious idling problems — ran an idling experiment, freezing three cars to minus eighteen degrees Celsius and then driving each one the same distance. Sometimes the cars were idled five minutes before driving, and sometimes ten minutes. The result was that the more idling time, the more wasted fuel.

“The test results demonstrated that with a 5-minute warm-up total fuel consumption enlargened by seven to fourteen percent and with a 10-minute warm-up total fuel consumption enhanced by twelve to nineteen percent,” the agency reported.

The Department of Energy’s Argonne National Laboratory, which has also conducted much research on idling, reported that “idling fuel consumption is, of course, linear with time, and increases with engine size”:

Or to put it more bluntly: Whereas newer cars are permanently improving the miles they get per gallon driven, idling will always be stuck in place — using up gas, but getting no miles for it.

But it’s not just fuel waste, it’s the accompanying emissions. What does it look like when you have a entire population of people — or at least the northern belt of a country like the U.S. — idling their cars in winter?

A two thousand nine investigate in Energy Policy attempted to calculate the consequences. The researchers found that, overall, all types of vehicle idling — idling in winter, idling while waiting for someone or something, and idling in traffic — contribute a staggering 1.6 percent of all U.S. greenhouse gas emissions.

That number is “almost dual the total emissions for the metal and steel manufacturing industry,” the paper noted. (In fairness, since the explore was published vehicle fuel economy has improved, and fresh vehicle greenhouse gas emissions have declined, thanks to fresh regulations. So especially for fresh vehicles, this may somewhat blunt the overall effects of idling.)

That is not to say that all idling should be stopped instantaneously. Some idling — particularly in traffic — may be unavoidable. But the other two categories of idling — in winter and while waiting — make a lot less sense. And the investigate found that they account for almost half of all U.S. greenhouse gas emissions attributable to idling.

And no wonder: When 1,300 Americans were surveyed about idling for the probe, almost half reported both idling their cars for longer than thirty seconds to warm them up and idling for more than thirty seconds because of waiting. Indeed, the average amount of time that respondents thought you should idle your car before driving, when it is lower that thirty two degrees Fahrenheit outside, was Five.01 minutes! And since that’s the average, many people thought you should idle for a lot longer than that.

“These values indicate that beliefs about how much idling is suitable or desirable are very twisted,” the authors wrote.

The explore found that if people would just knock off unnecessary idling of this sort, then consumers as a entire would save $Five.9 billion per year on fuel costs (based on the cost of fuel in 2008). The saved emissions, the probe noted, would be “larger than the emissions from the soda ash, aluminum and limestone industries combined.”

Idling behavior, the paper concluded, is “worthy of policymakers’ attention.” Some have taken note. For example, often-freezing Minneapolis has an anti-idling statute that restricts all non-traffic idling to three minutes per hour (with some exceptions). Anti-idling laws across the country vary, but some localities go after a similar course. So idling isn’t just pointless — beyond a point, it may even trigger a hefty fine.

Meantime, technological advances, and the thrust for ever greater fuel economy, are even beginning to help deal with the most unavoidable type of idling: Idling because you’re stuck in traffic. Vehicle start-stop technology literally shuts down the engine when your car is stopped, and automatically switches it on again when you begin to drive again. This technology tends to be found in hybrids but has spread to other cars as well. GM now boasts that ninety seven percent of buyers of a two thousand fourteen or two thousand fifteen Chevy Malibu bought a car with start-stop technology.

So, it’s hard to see any redeeming value to idling your car in winter. For the final word on the dumbness of this practice, let’s turn to the late Tom Magliozzi, the never-to-be-forgotten co-host of NPR’s “Car Talk.” As he put it to a Boston listener named Lisa, who had asked about her beau’s conviction that you need to idle up to ten minutes in winter:

“Dear Lisa’s Bf: You have your head so far up your tailpipe on this one, it may be coming out your air intake.”

Update: Many readers have responded to this lump by raising some good and interesting points. In particular, some folks have noted that they idle their cars in winter not for the sake of the engine, but rather for convenience (warmth) or because it helps in defrosting. While this article was focused solely on the energy and fuel consequences of idling, I acknowledge these other reasons. That said, the research cited above does suggest that many people think idling is necessary for their car’s engine, not for convenience or safety. So please, click the links if you have more questions about idling (here’s EPA and DOE, and here’s Argonne National Laboratory), and have a blessed and safe driving practice this winter!

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