How Long Can a Car Idle With the Heat On?

It depends on a lot of different factors, including how old your car is and how well it’s maintained.

It also depends on how cold it is outside.

Most modern cars won’t overheat when idling for extended periods of time, but if you’re out in the middle of a blizzard, or even just in a normal cold snap, your car will definitely start to lose heat faster than normal.

For this reason, you should always turn off your car when you’re not driving it in extreme weather conditions.

Why do cars idle?

To keep the engine warm while you’re parked

To keep the battery charged

To keep the oil flowing

How much electricity does a car use while idling?

By law, every car sold in the United States must be equipped with an idle reduction system that automatically turns off the engine when the vehicle is stopped for more than two seconds.

But the systems aren’t perfect, and many people still don’t know how to use them properly.

Even if your car has an idle reduction system, it can still use electricity while you’re waiting for traffic lights or stuck in rush-hour traffic.

The amount of electricity varies depending on how old your car is and where it’s parked some cars might take as little as 0.5 kilowatt-hours per hour. while others could use up to 1 kWh/hr when they’re stopped in traffic.

Why should you not idle your car for long periods of time?

When you’re driving, your engine does not need to be running at full power in order to get from point A to point B you can switch off the engine when stopped at a traffic light or in heavy traffic.

But when you’re parked with the engine running for an extended period of time, the vehicle’s fuel consumption will dramatically increase.

Idling also produces unnecessary greenhouse gas emissions that contribute to global warming.

One study found that idling accounts for about 20% of urban air pollution emissions!

What are the dangers of idling?

When you idle your car for more than 10 seconds, it wastes more gas than restarting the engine.

Idling also causes increased pollution from carbon dioxide and other toxic emissions.

The air inside a vehicle can be up to 40 times more polluted than outdoor air so leaving your car running in an attached garage can have serious health implications for those living in the home.

Turn off the engine if you’ll be stopped in one place for more than 10 seconds this includes drive-thrus, waiting at school drop-off or pick-up lines, train crossings, and traffic lights.

What are the effects of idling?

Idling is bad for the environment, and it’s bad for your car. Idling wastes gas and increases fuel consumption, Idling also causes your engine to overheat and decreases your car’s gas mileage by up to 20%.

Car idle with the heat on

Depends on the model of the car. Generally speaking, newer cars have better fuel efficiency than older cars, so they’ll be able to idle longer before they need to be restarted.

However, there are many other factors that come into play when determining how long your car can idle with the heat on.


You can idle your car as long as you want, but it’s not going to make any difference if you’re trying to keep warm.

You’re better off turning the heat off and driving around so that you don’t waste fuel.

Steven Hatman
Steven Hatman

We break down every information into easy-to-understand articles that cover all the categories anyone who owns a car needs to know about, such as oil , brakes , tires and etc. Our car guide is free and updated regularly for you to use as a resource, not only when you have an issue with your car but even before buying a new or used car! We also give tips on what to look for in each category or part of your vehicle.