Cars Simplified: Everything Automotive Explained


A vehicle's grille is almost always an opening in the front designed to let enough air in to pass by the fins of the Radiator, which is necessary to cool the engine. Some vehicles only use vents (often the case in rear-engine and mid-engine vehicles) for this purpose, and air-cooled engines don't have a radiator, but still use air from the grille for cooling purposes.

The position of the grille in relation to the front bumper can affect how much air gets through it, as well as how much mesh material it consists of and its angle.

Before Grilles

Early vehicles had radiators placed right up front so that the radiator itself formed part of the body shape. The air still had to pass through the radiator and end up in the engine bay, but the body wasn't used to cut down on how much air entered the radiator.

The 1932 Ford Model B Coupe pictured at the right has a radiator style grille, where the front has a radiator shape but isn't actually a radiator. Note the color seen through the lower portion. This was a styling choice during the transition from radiator-front designs to the grille design of modern vehicles.

Active Grille Shutters

Active grille shutters, also known as active air management systems, are a feature found on some modern cars that help to improve fuel efficiency and reduce emissions. These shutters are located in the front grille of the vehicle and are designed to open and close based on the needs of the engine.

When the engine is cold, or when the car is traveling at high speeds, the shutters are closed to help reduce aerodynamic drag and improve fuel efficiency. This is because the closed shutters reduce the amount of air that enters the engine bay, which in turn reduces the amount of fuel required to power the car. When the engine is warm and the car is traveling at lower speeds, such as when driving in the city or on the highway, the shutters are opened to allow more air to flow into the engine bay. This helps to cool the engine and improve performance.

Some active grille shutters can easily be seen functioning, while others are less visible and embedded deeper within the grille.

Grille Function In Motorsports

The grille is a necessary disadvantage in many forms of racing; although it is allows for air to come through the radiator for cooling, the radiator itself generates a lot of drag and after passing through it, the air has to find its way through the engine bay.