A shaped section of the rear underbody that smoothly transitions high-velocity airflow under the car back into the ambient atmosphere. By expanding the air as it exits, it creates a low-pressure area that effectively sucks the vehicle down onto the track. It provides significant grip at high speeds without adding the heavy aerodynamic drag associated with large rear wings.
Heard on the job
The customer backed into a curb and cracked the carbon fiber diffuser.
Related terms
Spoiler
An aerodynamic device mounted on a vehicle body to disrupt unfavorable air movement and reduce drag or lift.
Ground clearance
The vertical distance between a flat driving surface and the lowest point of a vehicle chassis.
Whale tail
A massive, flat rear spoiler with raised rubber edges designed to generate aerodynamic downforce.