Automobiles are powered by an internal combustion engine that uses gasoline or other fuel to turn the wheels of a vehicle. They usually have four wheels and seat one to eight passengers. Modern automobiles have become complex technical systems consisting of many subsystems that employ breakthroughs in design and new technologies including electronic computers, high-strength plastics, and advanced alloys of steel and nonferrous metals. They are the dominant mode of personal transportation worldwide.
The automotive industry is one of the world’s largest industries, and it provides jobs to millions of people around the globe. It is also responsible for a large proportion of the world’s energy consumption, and it consumes raw materials and creates waste that must be processed or stored away.
The automobile has changed society by enabling middle-class families to purchase their own cars. This has opened up a new world of leisure activities and services, such as hotels, restaurants, amusement parks, and recreation areas. It has spawned new industries in the manufacture of parts and vehicles, as well as improvements in road and highway construction. It has also brought harm to the environment in the form of exhaust emissions and has created new government requirements for safety features, licensing, and driving rules.
From the late 1600s onward, scientists and inventors have been working to develop a “horseless carriage”. Until the early 1900s it was not clear which of three power sources would be most commercially viable for automobiles: steam, electric power, or gas. The first Mercedes model was highly advanced in terms of engineering, but cost a fortune; the 1901-1906 one-cylinder, three-horsepower Tiller-steered Oldsmobile was merely a motorized horse buggy.
In the United States, the advent of Henry Ford’s Model T in 1908 revolutionized automobile manufacturing. He used innovative assembly line techniques in his Highland Park, Michigan plant to streamline production and reduce the price of his automobile until it was affordable to most middle-class Americans. This was the beginning of mass personal “automobility.” Today, 1.4 billion cars are in operation worldwide, traveling more than three trillion miles (4.8 trillion kilometers) on average each year. For many, it would be inconceivable or at least very inconvenient to live without a car.