X
CNET logo Why You Can Trust CNET

Our expert, award-winning staff selects the products we cover and rigorously researches and tests our top picks. If you buy through our links, we may get a commission. Reviews ethics statement

How to warm up your car safely: Remote car starters, block heaters and other solutions

A few tips on how to keep your car warm and secure, even in the coldest months.

Amanda Push Contributor
Amanda Push is a writer based in Colorado who covers personal finance, technology, safety and security, moving, and more. Her writing has also been featured at TheSimpleDollar.com, Interest.com, MyMove.com and Safety.com.
Amanda Push
4 min read
gettyimages-1148164186
Alem Omerovic/EyeEm/Getty Images

With temperatures dipping well into the negatives during the winter, it's no wonder some people don't mind leaving their vehicles running in their driveways for a while. After all, who wants to sit in a car shivering? But desperation to shake the cold can leave you exposed in other ways.

Leaving your keys in the ignition can get you locked out of your own car -- or worse, can lead to your car being stolen. That isn't the only concern, either: Idling for long periods can waste oil, drain your battery and even decrease your car's performance. There are plenty of straightforward ways to safely warm up your car, however, even if you leave it unsupervised.

Should you warm up your car?

The biggest reason most of us want to warm up our car is that we don't want to be cold while driving. In frigid winter weather, this is totally understandable. While it may heat up the inside of your car and defrost your windows, letting your car idle outside for 10 minutes can open you up to a variety of problems.

First, it's important that you warm up your car in an open space, to avoid the buildup of noxious fumes. That means open your garage door at least, and maybe even back the car out into the driveway.

Second, idling for a long time wastes resources and can actually lead to more wear on your engine. Yes, you might've heard that warming up your car for a few minutes is good for your motor. And in the past, when cars relied on carburetors, that was true. But today, with most vehicles using fuel injection in their motors, that simply isn't the case anymore.

vlcsnap-2018-09-16-17h36m40s928

Motor oil flows throughout the engine to help it function effectively.

Brian Cooley/Roadshow

Driving your car is the fastest way to warm it up, and generally, as long as you're not accelerating wildly within the first 30 seconds or so of driving, your engine will perform just fine from go.

Two exceptions: If you have a much older car that uses a carburetor (it'd probably have to be at least 30 years old), or if you have a vehicle with a diesel engine, you may need to warm it up a little more before starting it, especially at very low temperatures. An engine block heater -- a sort of space heater that helps your car's inner workings get to a warmer temperature before you start its engine -- is one solution to this problem.

Block heaters range in price, but you can find many for under a hundred bucks. By using a block heater, you can avoid some of the engine troubles that otherwise accompany super low temperatures.

Some devices even allow you to program them, to time the heating perfectly for when you need it most. When the block heater is applied, motor oil begins to warm up, helping the engine get ready to turn over without sustaining any damage.

2021-bentley-flying-spur-v8-156

Many remote starters come with extra security measures, to make sure a thief can't simply drive away with your running car.

Daniel Golson/Roadshow

Ready up, remote start

Another risk of leaving your car idling outside is having it stolen. Luckily, safely remote-starting your car from inside your home is possible.

Remote car starters, or remote engine cranks, are devices that start your engine after receiving a signal from your remote. This remote can be used from a considerable distance and can save you the hassle of having to go outside and start your car beforethe cabin becomes suitably warm.

If you're thinking of buying a remote car starter, look for one with extra security features, such as integrated alarm functions and horn honking/light flashing features.

What about electric vehicles?

Electric vehicles bring a whole new angle to the conversation of warming up your car, as they don't use traditional internal combustion engines. That said, warming them up can be just as important, from a convenience and mechanical standpoint.

From the convenience angle, many EVs can be scheduled to warm up in your garage at a certain time -- not by draining their battery, but rather by drawing from the electrical grid itself. Some vehicles allow you to select this feature in their apps. That means you won't be freezing for the first 10 minutes of your commute.

The other reason to warm up an EV is to get the battery to the optimal temperature for receiving a charge. Most cars simply do this automatically, not only when parked in your garage awaiting a scheduled charge, but also as you drive to a charging station -- if you've scheduled it on your app.

The verdict

We get it -- it's really cold outside. Who wants to drive around in a car so chilly they can't feel their fingertips? But don't let your discomfort override your safety. If you really need that car to be warmed up, keep your doors locked and use a remote starter instead of leaving your keys in your car -- and definitely don't just leave it in your garage. If your car runs on diesel or has a carburetor, consider getting an engine block heater. And if you have an EV, take a closer look at the options in your car's app.

If you're interested in learning more about making your car safer and more convenient, read our recommendations on remote car starters, emergency kits and jump-starters.