Downforce

Downforce is aerodynamic force that presses a car downward as it moves through the air. The force increases tire grip on the road, enabling higher cornering speeds and better braking performance. Downforce is generated through various aerodynamic surfaces: rear wings, front splitters, rear diffusers, underbody venturi tunnels, and the overall body shape.

The relationship between downforce and drag is fundamental to aerodynamic engineering. More downforce typically requires more drag (reducing top speed and fuel economy). Race cars optimize for the specific track and balance downforce and drag accordingly. Production sport cars typically have moderate downforce designs that balance lap time and daily driving practicality.

Modern road car downforce examples include the Lamborghini Aventador SVJ (with active aerodynamics making over 800 pounds of downforce at 175 mph), the Porsche 911 GT3 RS (with rear wing and large rear diffuser), and the Mercedes-AMG GT Black Series (with adjustable rear wing and front splitter). Active aerodynamics, where wings and panels move based on speed and driving condition, are increasingly common in modern performance cars.