How Long Does it Take to Warm Up Your Car? (Is It Necessary?)

You may have heard the advice to warm up your car before you drive.

But, is it really necessary and if so, how long you should do it for?

Learn everything you need to know below.

Should You Warm Up Your Car Before Driving?

The short answer is no, you don’t need to warm up your car before you drive.

While this practice is common in many cold climates, its necessity is a myth unless your car has a carburetor.

Otherwise, no matter what climate you live in, modern cars—built in the last 30 years—do not require warming up. 

It is, however, a good idea to avoid excessive engine revving in the first 15 minutes of operating your car after starting it, as that’s how long it takes for your engine to perform at optimal levels.

Otherwise, you’re good to drive your car at all speeds, including on the freeway, without warming it up.

The practice of warming up your car before driving it originated from older car designs and technology.

In the past, carbureted engines needed to be warmed up in order to allow an efficient mixture of fuel and air to enter a cold engine.

Modern cars are built with fuel injection systems that have technology to calculate the appropriate amount of gas and air needed to start an engine.

With this automatic process, modern cars have the right amount of gas needed to drive immediately after you start your engine.

If your goal of idling your car is to defog your windows, turn your car’s defroster on instead. It’s commonly believed that idling your car alone will do this, but it can actually make the fog worse. 

How Long Does it Take for a Conventional Car to Warm Up?

Most experts would say it’s not necessary to warm up your car, but if you really want to, you should wait no longer than 30 seconds after starting it to rev your engine.

Warming up your car for any longer than that can have negative effects. 

Negative Effects of Warming up a Car

There are several negative outcomes of warming up your car longer than necessary, including:

1. Wasting Fuel

Powering your car up and letting it idle consumes a considerate amount of fuel—an estimated half gallon per hour.

If you’re doing this often, the cost of gas wasted will add up quickly. 

With gas prices so high, conserving fuel and getting as far as you can per gallon of gas is important.

2. Emissions and Air Pollution 

Idling your car to warm it up adds unnecessary emissions to the environment.

According to the US Department of Energy, idling your car for over 10 seconds drains more fuel and increases more emissions that contribute to smog and climate change than stopping and restarting your engine does. 

3. Harm to Your Engine

Idling your car can accelerate wear and tear that causes damage to your engine’s cylinders, spark plugs, and emissions system.

This is because when your fuel injection system pumps too much gas into an idled engine, that strips it of oils necessary for it to operate correctly. 

And, the more your engine is running, the more wear it’s putting on itself.

Should You Warm up an Electric or Hybrid Car?

If your car is electric or a plug-in hybrid, it is OK — but also not necessary — to warm it up.

A warm-up may improve your car’s battery life and help add range.

While a classic car engine is okay in the cold, a battery doesn’t function properly in frigid temperatures—causing it to provide less power and not charge as quickly. 

To ensure optimal battery performance in cold weather, allow the car to reach a higher temperature before you start driving or charging your vehicle.

You can let it idle for a minute or two while it is plugged into grid power before you start your journey.

But again, if skipping a warm up will probably not cause you any problems.