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How Long Do You Need to Warm Up Your Car?

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Credit: GMC

That howling wind outside portends an especially cold day outside. Your poor car has been sitting in it, and you fear it may have trouble starting. Should you start it to let it warm up? Is that even necessary? What impact on the environment will idling your car have? Here’s what you should know:

Do You Need to Warm Up Your Car?

The answer is almost always no. Thanks to the way modern cars are built, it’s no longer necessary to let your car warm up before you start driving. And remember, once you have started it, avoid excessive engine revving – that’s no good for the engine. (This is true in warm weather, too.)

How Long Should You Let Your Car Warm Up?

Within seconds, your car is ready for everyday driving so that you can reach highway speeds immediately. Some experts recommend letting your car idle for up to 30 seconds before getting going, but that’s the longest you should wait. Any longer than that, and you’re just wasting gas.

Excessive idling will reduce your fuel economy. Colder air alone makes it more challenging for your vehicle to attain those numbers, and excessive idling certainly does not help.

Why You Shouldn’t Let Your Car Idle to Warm It Up

Fuel consumption

Idling your car consumes fuel —according to the U.S. Department of Energy, you will consume anywhere from one-quarter to one-half a gallon of fuel for every hour your car idles. If you idle your vehicle daily for 10 minutes before leaving for work and do so for three months out of the year, then that’s 660 minutes or 11 hours of wasted gas (22 days per month x 3 months). Up to 5.5 gallons of gasoline is waste; with it, $20 you could have spent elsewhere.

Pollution

Idling also contributes to emissions that pollute the environment. And that’s one reason why policymakers have implemented various idling reduction programs to cover school buses and fleet vehicles. Likewise, your daily 10-minute warm-up contributes a pound of carbon dioxide to the air, contributing to climate change.

Engine wear

Besides wasting fuel and polluting the air, a third factor should be considered when idling your car: engine wear. Excessive idling can take its toll on your engine, affecting the cylinders, spark plugs, and emissions system.

If you are idle for more than 30 seconds — such as at a stop light or train tracks. You will use less gasoline restarting the car than when idling, which is why manufacturers have installed automatic stop/start technology on several vehicles.

Why Did We Use to Warm Up Cars?

Allowing cars to warm up on cold days is a tradition that goes back decades to when vehicles had carburetors.

Then, warming up the car made sense, as it could take several minutes for the right blend of air and fuel to be delivered to the engine. Without the correct blend, cars would sputter, stall, and leave drivers stranded.

By the late 1980s and indeed,y no later than the early 1990s, all car manufacturers completed the transition to electronic fuel injection. Sensors working with injectors ensured that the right air-fuel mix was delivered promptly. Therefore, warming up cars equipped with fuel injection systems became unnecessary.

Should a new car still have trouble starting promptly, other factors such as a clogged injector, a frozen fuel line, or a dead battery might be the culprit. But those are issues separate from the topic at hand.

Read 8 Reasons Your Car Won’t Start

Unfortunately, certain habits are challenging to break, and misinformation is rampant. Chances are,e if you had one of those older models and later sold it, you passed this habit on to the next generation. It is time to lay the fallacy to rest, especially for any car built within the past 25 years.

Do You Need to Warm Up Electric Cars?

You don’t need to warm up electric cars, but it can help add range and improve your battery life.

Electric car batteries don’t like the cold, so they don’t provide as much power or charge quickly when the temperature drops.

One way to improve battery performance in cold weather is to precondition the battery. Preconditioning means allowing it to reach an optimal temperature before you start driving or charging.

It’s best to leave the car plugged in while you precondition the battery. That way, the vehicle uses the power from the outlet to warm up the battery instead of the power from the battery itself, leaving more of the battery’s charge for driving.


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