External Sunshades Cool Cars Better Than Internal Ones, Study Finds

Parking a car in the sun can quickly turn its interior into an oven, but the color of the vehicle and the use of sunshades play a role in how hot it gets. A study by the German Automobile Club (ADAC) investigated these factors.

The research found that while dark-colored cars absorbed more heat, with their surfaces reaching 65 degrees Celsius compared to 44 degrees on white cars, the difference inside the cabin was less dramatic. The interior of the black car was only five degrees warmer than the white one.

When it came to sunshades, the study revealed a clear difference in effectiveness. An internal sunshade, even when covering most of the windshield, offered minimal cooling, reducing the cabin temperature by only four degrees Celsius compared to a car without one. In contrast, an external sunshade proved much more effective, keeping the interior eight degrees cooler. A full-coverage shade protecting the entire vehicle offered even better results, reducing the interior temperature by ten degrees.