What Is an F1 Diffuser?

A diffuser is an integral part of the engineering of a race car, including Formula 1 race cars. Diffusers are important in producing down force and aerodynamic grip.

  1. Position

    • A diffuser is positioned at the rear of the F1 race car between the rear wheels, acting as an extension of the floor of the car. Diffusers are used to gather and organize the air that travels at high speed under the car as it moves.

    Pressure

    • As an F1 car travels at high speed, air moves above and beneath its wing section, with air traveling underneath the wing moving faster than that above. The difference in air speed above and below the wing alters the pressure of air, with higher pressure above pushing down. This down force creates more grip when an F1 car is cornering; without this down force the car would rely only on its tires and suspension to remain on the road.

    Rules

    • The governing body of Formula 1 introduced rules in 2009 in an attempt to reduce the amount of down force being created by F1 race cars, which included alteration to diffusers. The height of the three channels used to move air under the car was increased from 4.9 inches to 6.9 inches. The diffuser was moved back 13.8 inches behind the rear axle, where it had previously ended in line with the rear axle.