Tested: How Much Does a Sunshade Cool a Car?

Look across any parking lot on a hot summer day and you’re likely to see those shiny, reflective sunshades on dozens of cars. In a struggle to keep cars cool in the heat, these shades have become the go-to defense… and for good reason.

Why are these shades so popular? First and foremost, they work. By reflecting sunlight back out of the car, they keep it from reaching the interior of the automobile and heating up interior components like the dashboard.

Secondly, sunshades are a cheap way to keep your car cool in the summer heat. Sunshades can be had for as little as $10 on Amazon, making it an affordable way to keep your car more comfortable when it’s hot out. It’s a small price to pay for being cooler.

All that said, we wanted to see exactly how much cooler a car can be using a sunshade versus without. So we put it to the test. Parking a truck in direct sun on a 98-degree afternoon, we learned exactly how important these shades are in keeping the sun from heating up your car.

Testing an Auto Sunshade on a Summer Day

While we normally park our car in the garage, we always use a sunshade when having to park outside during the summer. Anecdotally, it’s always felt cooler when we got inside compared to when we forgot to use the shade.

In this case, we first took baseline temperature readings of the ambient air as well as focused measurements for the seat and dash temperature. During the afternoon we tested, the outside temperature was 98 degrees and the weather was sunny. In other words, unless you live in a place like Phoenix or Austin (where we live), then these conditions are about the worst that you’ll face.

Baseline Temperatures

Inside the garage, the temperature was in the low 90s. As you would expect, the car sitting in the garage has similar readings:

Base temperature of a car in garage
The temperature inside the car while sitting in the garage.

Meanwhile, the cloth seats and the plastic dashboard has temperatures hovering around 100 degrees while sitting in the garage:

Dash temperature in garage car
The dash temperature inside the garage.

Pulling the car into the driveway, it was obvious that we were going to battle significant heat. In the 30 seconds it took to back the car out of the garage it was already getting uncomfortable with the air conditioner off.

Temperatures With a Sunshade

Sunshade installed in front window of a car

With the car sitting in full sun, we put the accordion style sunshade to the test. With all windows up and doors closed, we let the car sit for 45 minutes. At the end of that time the temperature inside the car had climbed from the low 90s to 106 degrees.

Temperature inside car with a sunshade
The car reached 106 degrees after 45 minutes with a sunshade installed.

The hottest spot in the car was the dash behind the sunshade, where we recorded a temp of nearly 116 degrees. That’s 16 degrees hotter than the dash when sitting in the hot — but shaded — garage.

Dash temperature in car with sunshade
The dash reached 116 degrees with the shade installed.

By any means, it’s obvious that parking the car in full sun caused a significant increase of about 15 degrees in total. But how does that compare to not using any sunshade at all?

Temperatures Without a Sunshade

Car baking in sun without sunshade

After seeing the initial results with the sunshade, we removed it for our final test. Then, we let the car sit in full sun with no protection for another 45-minute period. The results were eye-opening.

Temperature inside a hot car
Temperatures in the car hit 116 when the sunshade was removed.

After 45 minutes, the temperature inside the car rose to 115 degrees — about 10 degrees warmer than with the shade. But what stood out the most is that the temperature of the dashboard, which sat baking in direct sunlight, warmed to a scorching 156 degrees.

Temperature of dash inside hot car
On a 98 degree day, the dash warmed to 156 degrees.

Keep in mind that with the dashboard so hot, even starting the car up and turning on the air conditioner, the dash would continue to radiate heat into the car.

Is a Sunshade Worth It?

On a 98-degree day with full sun, it showed just how important using a sunshade is in keeping your car cool. Not using a shade increased the temperature in the car 10 degrees… and the temperature of the dash a staggering 40 degrees. Check out the full results:

Auto sunshade test results

Considering that sunshades only cost between $10-20 on Amazon and can keep your car much more comfortable in the summer heat, it’s a no brainer that you should be using one every time you park your car.


Please enter your comment!
Please enter your name here