Bumper (car)
A bumper is a structure attached to or integrated with the front and rear ends of a motor vehicle, to absorb impact in a minor collision, ideally minimizing repair costs.
Early car owners had the front spring hanger bolt replaced with ones long enough to attach a metal bar.
On the 1968 Pontiac GTO, General Motors incorporated an "Endura" body-colored plastic front bumper designed to absorb low-speed impact without permanent deformation.
[9] Bumpers of most modern automobiles have been made of a combination of polycarbonate (PC) and acrylonitrile butadiene styrene (ABS) called PC/ABS.
[citation needed] Bumpers offer protection to other vehicle components by dissipating the kinetic energy generated by an impact.
Front bumpers, especially, have been lowered and made of softer materials, such as foams and crushable plastics, to reduce the severity of impact on legs.
The U.S. trucking industry has been slow to upgrade this safety feature,[16] and there are no requirements to repair ICC bars damaged in service.
[24] Mismatches between SUV bumper heights and passenger car side impact beams have allowed serious injuries at relatively low speeds.
Regulations for automobile bumpers have been implemented for two reasons – to allow the car to sustain a low-speed impact without damage to the vehicle's safety systems, and to protect pedestrians from injury.
[30] International safety regulations, devised initially as European standards under the auspices of the United Nations, have now been adopted by most countries outside North America.
[33][34] In the European Union, the sale of rigid metal bull bars that do not comply with the relevant pedestrian-protection safety standards has been banned.
[36][37] In 1971, the U.S. National Highway Traffic Safety Administration (NHTSA) issued the country's first regulation applicable to passenger car bumpers.
215 (FMVSS 215), "Exterior Protection," took effect on 1 September 1972—when most automakers would begin producing their model year 1973 vehicles.
[39] The requirements effectively eliminated automobile bumper designs that featured integral automotive lighting components such as tail lamps.
They ranged from non-dynamic versions with solid rubber guards, to "recoverable" designs with oil and nitrogen filled telescoping shock-absorbers.
The 1973 AMC Matador coupe had free-standing bumpers with rubber gaiters alone to conceal the retractable shock absorbers.
[44] "Endura" bumpers, compliant with the regulations yet tightly integrated into the front bodywork, were used on models such as the Pontiac Grand Am starting in 1973 and the Chevrolet Monte Carlo starting in 1978, with significantly lower mass than heavy chromed-steel bumpers with separate impact energy absorbers.
With exceptions including the Volvo 240, Porsche 911, and Rolls-Royce Silver Shadow, European and Asian automakers tended to put compliant bumpers only on cars destined for the U.S. and Canadian markets where the regulations applied.
U.S. bumper-height requirements effectively made some models, such as the Citroën SM, ineligible for importation to the United States.
[49] The recently elected Reagan administration had pledged to use cost–benefit analysis to reduce regulatory burdens on industry, which impacted this standard.
[50] As discussed in detail under Physics, before 1959, people believed the stronger the structure, including the bumpers, the safer the car.
[56] In the United States, the Insurance Institute for Highway Safety (IIHS) subjects vehicles to low-speed barrier tests (6 mph or 9.7 km/h) and publishes the results, including repair costs.
The results illustrate the effect of the changes to the U.S. bumper regulations (repair costs are quoted in 1990 United States dollars):[56] Today's bumpers are designed to mitigate injuries to pedestrians and minimize weight at the ends of the vehicle, thereby increasing occupant protection from progressive crumpling in a serious accident.
[59] They are no longer made of steel and rubber,[59] but of a plastic outer fascia over a lightweight, impact-absorbing polystyrene foam core.
