Few inventions have had a more profound effect on modern life than the automobile, a four-wheeled vehicle used for transporting people. Once the domain of wealthy urbanites, cars are now a staple of the global economy, driving 4.8 trillion kilometers (three trillion miles) every year and fueling a wide range of other industries that supply the vehicles with parts, accessories and fuel. Many activities, from business to vacation travel, would be inconceivable or inconvenient without the automobile.
The modern car is usually powered by a water-cooled, piston-type internal combustion engine fueled by gasoline and producing power through the wheels, whether they are front-wheel driven or all-wheel driven. Some engines are air-cooled, but they are less efficient and generally not as reliable. In addition to the internal combustion engine, most automobiles are equipped with a transmission system, electrical system and cooling and lubrication systems.
Other systems in an automobile include the suspension system, which holds the wheels above the road surface and absorbs the shock of bumps or unevenness; and the braking system, which slows and stops the car. In addition, the body provides a place for passengers to sit, offers storage space and houses the automobile’s systems.
Research and development engineers have continually sought to improve the safety, performance, energy efficiency and design of the automotive industry’s most popular products. For example, a new design may incorporate electronic control systems to improve handling and reduce the risk of accidents. A more efficient engine might use smaller quantities of fuel and emit fewer pollutants than the previous model.
The first modern automobiles were developed in Germany and France toward the end of the nineteenth century by such men as Gottlieb Daimler, Karl Benz and Nicolaus Otto. The gasoline-powered automobile quickly overtook the streets and highways of Europe and America, and American automobile manufacturers innovated mass production techniques. By the 1920s, Ford, General Motors and Chrysler emerged as the world’s top producers.
Having your own car gives you freedom and independence to go where you want when you want. You don’t have to rely on other people or public transport, and you can leave earlier in the morning to ensure that you get to work or classes on time. Having your own car also saves you time when shopping or visiting friends and family, as you no longer have to wait for the bus or worry about missing it.
The automobile has become an integral part of many cultures, influencing the design of cities and creating an entire industry of spin-off activities, such as those that manufacture tires or provide repair services. It is the most widely owned mode of transportation, with some 520 million registered worldwide in 2002, including nearly 140 million in the United States. In addition to cars, the term automobile has been applied to similar devices, such as motorized scooters and golf carts. In the United States, the term usually refers to passenger cars with seating for one to seven people.