The hood (

American English American English, sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. English is the most widely spoken language in the United States and in most circumstances ...

) or bonnet (

Commonwealth English The use of the English language in current and former member countries of the Commonwealth of Nations was largely inherited from British colonisation, with some exceptions. English serves as the medium of inter-Commonwealth relations. Many ...

) is the

hinged A hinge is a mechanical bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation: all other ...

cover over the engine of

motor vehicle A motor vehicle, also known as motorized vehicle or automotive vehicle, is a self-propelled land vehicle, commonly wheeled, that does not operate on rails (such as trains or trams) and is used for the transportation of people or cargo. The ...

s. Hoods can open to allow access to the engine compartment, or trunk (boot in

) on rear-engine and some mid-engine vehicles) for maintenance and repair.

Terminology

In British terminology, ''hood'' refers to a fabric cover over the passenger compartment of the car (known as the 'roof' or 'top' in the US). In many motor vehicles built in the 1930s and 1940s, the resemblance to an actual hood or

bonnet A Bonnet is a variety of headgear, hat or cap Specific types of headgear referred to as "bonnets" may include Scottish * Blue bonnet, a distinctive woollen cap worn by men in Scotland from the 15th-18th centuries And its derivations: ** Fea ...

is clear when open and viewed head-on; in modern vehicles it continues to serve the same purpose but no longer resembles a head covering.

Styles and materials

On front-engined cars, the hood may be hinged at either the front or the rear edge, or in earlier models (e.g. the

Ford Model T The Ford Model T is an automobile that was produced by Ford Motor Company from October 1, 1908, to May 26, 1927. It is generally regarded as the first affordable automobile, which made car travel available to middle-class Americans. The relati ...

) it may be split into two sections, one each side, each hinged along the centre line. A further variant combines the bonnet and wheelarches into one section and allows the entire front bodywork to tilt forwards around a pivot near the front of the vehicle (e.g. that of the

Triumph Herald The Triumph Herald is a small two-door car introduced by Standard-Triumph of Coventry in 1959 and made through to 1971. The body design was by the Italian stylist Giovanni Michelotti, and the car was offered in saloon, convertible, coupé, est ...

). Hoods are typically made out of the same material as the rest of the body work. This may include

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistan ...

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...

fiberglass Fiberglass ( American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cl ...

carbon fiber Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...

. However, some aftermarket companies produce replacements for steel hoods in fiberglass or carbon fiber to make the vehicle lighter.

Release/ safety and security mechanisms

The hood release system is common on most vehicles and usually consists of an interior hood latch handle, hood release cable and hood latch assembly. The hood latch handle is usually located below the steering wheel, beside the driver's seat or set into the door frame. On race cars or cars with aftermarket hoods (that do not use the factory latch system) the hood may be held down by hood pins. Some aftermarket hoods that have a latch system are still equipped with hood pins to hold the hood buttoned down if the latch fails.

Features

A hood may contain a

hood ornament A hood ornament (or bonnet ornament in Commonwealth English), also called, motor mascot, or car mascot is a specially crafted model which symbolizes a car company like a badge, located on the front center portion of the hood. It has been used ...

hood scoop A hood scoop (North American English) or bonnet scoop (Commonwealth English), sometimes called bonnet airdam and air dam, is an upraised component on the hood of a motor vehicle that either allows a flow of air to directly enter the engine co ...

, and/or wiper jets. A portion of the hood may be raised in a power bulge, to fit a large engine or air filters.

Pedestrian safety

In Japan and Europe, regulations have come into effect that place a limit on the severity of pedestrian head injury when struck by a motor vehicle. This is leading to more advanced hood designs, as evidenced by multicone hood inner panel designs as found on the

Mazda RX-8 The Mazda RX-8 is a sports car manufactured by Japanese automobile manufacturer Mazda between 2002 and 2012. It was first shown in 2001 at the North American International Auto Show. It is the successor to the RX-7 and, like its predecessors i ...

and other vehicles. Other changes are being made to use the hood as an active structure and push its surface several centimeters away from the hard motor components during a pedestrian crash. This may be achieved by mechanical (spring force) or

pyrotechnic Pyrotechnics is the science and craft of creating such things as fireworks, safety matches, oxygen candles, explosive bolts and other fasteners, parts of automotive airbags, as well as gas-pressure blasting in mining, quarrying, and demolition. ...

devices.

References