Originally, the grille was used to keep dirt and stone chips away from the actual radiator on the streets, which were often unpaved in the past. Stones hitting the cooling fins could cause damage and leakage. Dirty radiator fins would have a lower cooling effect than clean ones; the engine could overheat.
The air intake of most modern vehicles is located below the grille, so this has become a decorative element of the vehicle design . In times of similar formal idioms and concepts, they should demonstrate a certain independence of the brand. As part of the front of the vehicle, the radiator grille often determines the typical appearance of vehicles of a certain brand. Examples of this would be the BMW kidney grille , the Audi single frame and the Scudetto at Alfa Romeo .
The design of the radiator grille moves in the field of tension between design, its function as a cooling air inlet and its aerodynamics , on which the air resistance of the vehicle and thus also its fuel consumption depends. Since around the beginning of the 2000s, the radiator grilles have been growing in many new models, which worsens the drag coefficient due to the turbulence in the air flow . One approach to alleviating this problem is to use grills that have flaps that close at higher speeds.
- Hans-Hermann Braess, Ulrich Seiffert: Vieweg manual automotive technology . 2nd edition, Friedrich Vieweg & Sohn Verlagsgesellschaft, Braunschweig / Wiesbaden 2001, ISBN 3-528-13114-4