Thump, thump, thump, thump, thump. What is that annoying rhythmic sound that happens when you roll down your car window while driving? All you want is some fresh air without all the noise. Unfortunately, wind buffeting will likely continue unless you know how to stop it.

The science behind the noise

According to Erie Insurance, wind buffeting occurs because of Helmholtz resonance. When you open a window, sunroof, or moonroof in a moving vehicle, the air inside collides with the faster-moving air outside. That causes the two bodies of air to compress and decompress repeatedly. As they do, they create small wind vortexes (mini-tornadoes) to form because of the difference in speed. Fortunately, these tiny vortexes produce noise rather than destruction.

It’s this repeated compression and decompression of the air that causes the loud, rhythmic thumping that’s so annoying when all you wanted was some fresh air. Keep reading to learn what factors affect how much wind buffeting you’ll experience and how you can prevent it.

Factors that affect wind buffeting

Three factors affect how much wind buffeting you’ll likely experience while cruising down the road. Some you can’t change easily, like the type of vehicle you drive. Others, like the speed at which you’re traveling and the choice of window to open, are more within your control.

1. The size and shape of your vehicle

Newer, more aerodynamic vehicles produce louder wind throb than boxier models. That’s because the outside air hugs your aerodynamic car as it’s moving down the road. Anything that interrupts that smooth, efficient airflow, such as an open window or sunroof, will create wind buffeting on a magnified scale. The buffeting will also be louder because your aerodynamic vehicle seals more air inside — until you decide to let it out.

To see for yourself just how awful the sound can be, test-drive a Toyota Supra. This sports car is notorious for having the worst wind buffeting problem. 

2. Your driving speed

The faster you drive, the greater the difference in speed between the air inside and outside your vehicle. That difference causes more extreme wind vortexes that produce louder thumps. If your head is starting to throb in time with the thumps, you might want to slow down.

3.  Whether you’ve opened a back or front window

Wind buffeting is worse when you open one of the back windows because they lack side mirrors. Those side mirrors help redirect the airflow around the front windows, lessening the noisy effect of the airstreams when they collide.

How can you stop wind buffeting?

There’s actually an easy solution. Open another window in your car so that the air pressure stabilizes. If your newer vehicle has a terrible wind buffeting problem, like the Toyota Supra, you can add accessories to help control the noise issue. Simply place wind deflectors on the front edge of the back windows to redirect the airflow, just like the side mirrors do for the front windows.

You can also add inexpensive wind deflectors to your vehicle’s sunroof, too. Voilà—no more annoying thumping. Now you can enjoy a breath of fresh air without feeling like a helicopter is landing on your vehicle. Don’t you wish every car problem were this quick, easy, and painless to fix?