Even the operating range of a vehicle, one of the key factors for the success of e-mobility, depends on its drag coefficient.
Almost every design detail offers aerodynamic potential. For example, a relatively round front end with a long front overhang ensures optimized air flow around a Volkswagen. Thoroughly rounded A-pillars with a minimum of steps reduce buffeting. The same applies to a vaulted roof, especially if the highest point is as far to the front as possible. Narrow wheels with minimum air flow through the wheel and optimized tires form part of the overall aerodynamic package. The contribution of each detail can be determined precisely in the wind tunnel almost as if the vehicle were under a microscope.
The controlled storm around a vehicle is continually providing new information and opening up new areas of research. For example in the case of the driven axle, we have the phenomenon of ventilation drag. This is caused by a number of factors including the pressure distribution in front of and behind the wheel spokes and operates around the axis of a wheel even if the wheel is entirely closed.
There is also considerable potential for development in the last corners of the underbody cladding, the labyrinth of cooling air ducts, the consistency of painted surfaces and, of course, to the right and left of the A-pillars. The Cd value of a car can even be significantly improved by not installing exterior rear-view mirrors.