Aerodynamics is an offshoot of aircraft design and early wind tunnel testing. Early aircraft designers needed a way to predict how their designs would perform, and they started testing scale models in wind tunnels to test wind resistance and flight characteristics. Now aerodynamics is important in a number of applications besides aerospace engineering. It is a significant factor in vehicle design, including automobiles, vans, and trucks. . It is used to prediction of forces and moments in sailing, and in boat design. Structural Engineers use aerodynamics to calculate wind loads in the design of large high rise buildings and bridges. Urban aerodynamics seeks to help city planners and designers improve comfort in outdoor spaces and reduce the effects of urban pollution. The field of environmental aerodynamics investigates the various ways atmospheric circulation and flight mechanics affects ecosystems. The aerodynamics of internal passages and ducts is important in heating/ventilation, gas piping, and in auto engines where detailed flow patterns can strongly affect the performance of the engine.

Automotive aerodynamics is the study of the aerodynamics of road vehicles and off road vehicles. The main concerns is reducing drag, reducing wind noise, and preventing undesired lift forces which can occur at high speeds. For some classes of racing vehicles, it may also be important to produce downwards aerodynamic forces to improve traction and thus cornering abilities, keeping the car glued to the road.

An aerodynamic automotive will integrate the wheel and lights in its shape to have a small profile. It will be streamlined, and not have sharp edges crossing the wind stream above the windshield and will feature a sort of tail called a fastback or airfoil. The vehicle will have a flat and smooth floor to support the venturi effect, producing the desirable downwards aerodynamic forces. The air rams into the engine bay and is used for cooling, combustion, and passengers comfort, is then ejected under the floor. Automotive aerodynamics differs from aircraft aerodynamics in several important ways. The characteristic shape of a road vehicle is a sloped front compared to that of an aircraft. An automobile operates very close to the ground, rather than in free air. Vehicle operating speeds are lower, and as a ground vehicle, it has a lessor degree of freedom than the aircraft, so it is less affected by aerodynamic forces.

Automotive aerodynamics is now studied using both computer modeling and wind tunnel testing. For the most accurate results from a wind tunnel test, the tunnel is sometimes equipped with a rolling road. This is a movable floor for the working section, which moves at the same speed as the airflow. This prevents a boundary layer of air from forming on the floor of the working section and affecting the results.

The only bad thing about aerodynamics in auto design is that all the cars, having similar streamlined designs, look alike.