Featured Rear Diffuser

Diffusers, besides looking cool, create a low-pressure area behind the car, which accelerates the air passing through and lowers its density. This sucks the car to the ground like a vacuum, producing downforce and improving stability and fuel efficiency.

A diffuser's effect is most apparent in high-speed applications. There, it effectively creates an expansion chamber for air that doesn't generate large amounts of drag like a wing. This means that a properly shaped and angled diffuser can redirect airflow without the top speed penalty associated with high-downforce wing setups. Vehicles without diffusers have a low-pressure air pocket that forms behind them as they push through the air, creating turbulence and drag. Because a diffuser expands the air moving under the car and redirects it upward, that air will flow into this pocket and minimize its size, thus reducing drag.

Despite typically being associated with race cars, (i.e., cars with extreme aerodynamics), diffusers can actually benefit everyday vehicles as well, though not as drastically. On regular cars, these devices still perform the same job, reducing drag and improving stability at higher speeds for greater fuel efficiency and higher grip levels. Much like their racing counterparts, these effects only apply to properly shaped diffusers and generally improve the lower a car is to the ground, providing the highest benefits on low-slung sports cars, luxury sedans, and large commercial vehicles looking to maximize efficiency by decreasing that air pocket left in their wake.