Dirty air

Dirty air is the turbulent, low-energy airflow that peels off the back of a Formula 1 car and wrecks the aerodynamics of the car following it. Because modern cars generate grip from precisely managed airflow, a trailing car in dirty air loses downforce, slides its tyres and struggles to stay close enough to attack. It is the single biggest reason overtaking is hard, and the 2022 ground-effect regulations were written specifically to reduce it. The technical rationale is set out by Formula 1.