After discussing the elementary theory concerning aerodynamics, the boundary layer, drag, downforce, air density and gurney flaps are being explained. With the aid of explanatory calculations the influence of wing settings and undertrays are made clear. Also the influence of vortex generators and golf ball profiles on wings is shown. Furthermore the optimum aero balance is found, and an assessment is given of finding the drag and downforce values from (existing race) data, resulting in enlightening aero-maps and graphics. Finally an example of CFD simulation on a formula car is shown. Over the past fifty years, the application and continuousContinuous speed development of aerodynamicAerodynamic measures in racing cars have played a crucial role in significantly improving lap times. Nowadays, aerodynamic optimization plays a key role which almost all components of a racing car are subordinate to. The main objective is to increase the wheelWheel loadsWheelload on the tyres through downforceDownforce, to achieve higher corneringCornering speeds. However, this leads conversely to a negative effect of a higher air resistance (‘drag’), which reduces the maximum speed and acceleration capacity. For this reason, all aerodynamicAerodynamic measures lead to a compromise as an optimum, which can be described as an “aerodynamic compromise”. This compromise between contact pressure and air resistance must be determined individually for each racetrack.