In automotive world, a grille is an opening in the vehicle's bodywork to allow air to enter. Several vehicle models feature a grille at the front of the vehicle for the air intake to flow over the radiator and cool the engine parts. Other common grille locations include below the front bumper, near the wheels to cool the brakes, in the cowl for ventilation of cabin, or on the back of the deck lid in rear engine vehicles.
Some vehicles have what appear to be small grilles which are not used to duct air through the radiator. These grilles are intended for horns which allows the sound of the horn to be clearly heard up front.
The grille is often a distinctive styling element, and many marques use it as their primary brand identifier. For example, Jeep has registered its seven bar grille style as a trademark. Rolls-Royce is known for arranging its grille bars manually and by hand to ensure that they appear perfectly vertical. Other car makers known for their grille styling include BMW's split kidney, Alfa Romeo's 6 bar shield, Rover's chrome teeth grille, Volvo's slash bar type grille, Dodge's cross bar, Audi's latest, so-called single-frame grille, Bugatti's horse-collar and an egg-rate grill on late-model Plymouths. The unusual 1971 Plymouth Barracuda grille is known as a “cheese grater”. Ford's three-bar grille of the 2006 Fusion has become a distinctive grille as well.
The contrary styling pattern is also adapted. From the late 1930s, Cadillac would alternate its pattern from horizontal bars to a variety of patterns of cross-hatching as a simple way of making the car look new and different from year to year, for this make did not have a standard grille form. Sometimes there is a sort of style and fashion trend in grille bars. For example, in the early years after the second World War, most of the American car manufacturers generally switched to thicker and fewer grille bars.
A billet grille is an after market part and accessories that is used to enhance or modify the style or function of the original grille. They are usually sourced from billet, solid bar aircraft grade stock aluminum or stainless steel, although some are customized and machined from one solid sheet of aluminum.
Car customizers would modify the grille as a matter of choice in personalizing or “pimping” their car, taking the grille bar from another make and model. Even ordinary metal sheet with hole pattern for ventilation grating sold to households for repair has been used for the grille opening of custom cars.
Source: Wikipedia
