The hood (

American English American English, sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the United States. English is the Languages of the United States, most widely spoken lang ...

) or bonnet (

Commonwealth English The use of the English language in current and former Member states of the Commonwealth of Nations, countries of Commonwealth of Nations, the Commonwealth was largely inherited from British Empire, British colonisation, with some exceptions. Eng ...

) is the hinged cover over the engine of

motor vehicle A motor vehicle, also known as a motorized vehicle, automotive vehicle, automobile, or road vehicle, is a self-propelled land vehicle, commonly wheeled, that does not operate on railway track, rails (such as trains or trams), does not fly (such ...

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 Hood may refer to: Covering Apparel * Hood (headgear), type of head covering ** Article of academic dress ** Bondage hood, sex toy * Hoodie, hooded sweatshirt Anatomy * Clitoral hood, a hood of skin surrounding the clitoris * Hood, a flap of ...

bonnet A bonnet is a variety of headgear, hat or cap. Specific types of headgear referred to as "bonnets" may include Native American *War bonnet, feathered headgear worn as an earned military decoration by high-ranking Plains Indians United King ...

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 the Ford Motor Company from October 1, 1908, to May 26, 1927. It is generally regarded as the first mass-affordable automobile, which made car travel available to middle-class Americans. Th ...

) it may be split into two sections, one each side, each hinged along the centre line. Another variant combines the bonnet and wheelarches into one section which 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, es ...

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

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

aluminium Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

fiberglass Fiberglass (American English) or fibreglass (English in the Commonwealth of Nations, Commonwealth English) is a common type of fibre-reinforced plastic, fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened i ...

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 comp ...

. Some aftermarket companies produce replacements for steel hoods in fiberglass or carbon fiber to reduce vehicle weight.

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 or bonnet mascot in Commonwealth English), also called a motor mascot or car mascot, is a specially crafted model that symbolizes a car company, like a badge, located on the front center portion of the Hood ...

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 air to directly enter the engine compartment ...

, 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 2003 and 2012. It was first shown in 2001 at the North American International Auto Show#2001, North American International Auto Show. It is the direct s ...

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 fireworks, but also includes safety matches, oxygen candles, explosive bolts (and other fasteners), parts of automotive airbags, as well as gas-pressure blasting in mining, quarrying, and demol ...

devices.

References