Aerodynamic Efficiency: Ratio of downforce to drag.

Center of Gravity: The distribution of weight around a point of balance

Crash test: Test performed on cars to prove that they meet strict safety regulations.

Differential: Device within a car’s gearbox that allows the two rear wheels of a car to rotate at different speeds during cornering.

Downforce: Opposite of lift. A vertical force directed downwards, produced by airflow around an object. Downforce pushes a car or bike down onto the track to provide extra grip at high speeds.

Drag: A force acting on an object opposite to the direction of the object’s motion, produced by friction. Usually refers to the air resistance acting on airplanes and cars.

Friction: A force that impedes the slipping and sliding of two surfaces in contact. A skidding tire is a good example of friction at work.

Gearbox: Part of the transmission that changes the drive ratio between the engine and wheels to allow the car to have the maximum torque at all times.

Kinetic Energy: Energy of motion. The faster an object moves the more kinetic energy it has.

Lift: A force that acts upwards against gravity. Also refers to the upward reaction of an aircraft to the flow of air forced over the shape of the wing (airfoil).

Thrust: A forward force that pushes an object through the air

Turbulence: Turbulent airflow occurs when the flow breaks up into eddies and complex patterns. This can cause unstable forces on an object. As the airflow moves from the front of a car to the rear it becomes turbulent.

Vortex: A fluid that rotates around its own center. Turbulent flow is made up of many little vortices.

Wind tunnel: A large, tube-like structure created to test vehicle aerodynamics. Inside, a high-power wind is produced (usually by a large fan) to flow over the test object, such as a car, recreatng the effect of the car traveling at speed. Meanwhile, the car is connected to instruments that measure and record aerodynamic forces that act upon it.