A four-wheeled vehicle that is used mainly for passenger transportation and powered by an internal combustion engine using a volatile fuel, usually gasoline. The automobile is a common and familiar sight in the world, with more than 70 million units manufactured each year. Automobiles are the most widely produced of all modern technologies. This industry, with its specialized engineering, contributes significantly to the economy of many nations and is one of the largest and most profitable manufacturing sectors in the world.
Automobiles are used for a variety of purposes, including travel to work, school, shopping, visiting friends, and family. In recent years, the passenger car has become the primary means of transport for millions of people, especially in the United States. With more than three trillion miles (almost five trillion kilometres) traveled by cars each year, the automobile has become an important and necessary part of daily life.
In addition, automobiles provide a convenient form of recreation and entertainment. The automobile has also had a profound effect on culture and society, changing lifestyles and social attitudes. For example, families can now take vacations to remote destinations and explore pristine landscapes. Teenagers gain independence with their ability to drive, and dating couples enjoy the privacy of the automobile.
Invented in the nineteenth century, the automobile has had a profound impact on the world. Despite early difficulties with quality and reliability, automobile production has flourished. The American manufacturing tradition and cheap raw materials encouraged mass production, and the absence of tariff barriers facilitated sales over a large geographic area. The automobile revolutionized the economy and spawned dozens of spin-off industries. The demand for vulcanized rubber skyrocketed and highway construction brought thousands of new jobs.
Automobiles have been continuously improved, with technological developments enabling manufacturers to produce more reliable, efficient and safer vehicles. Today, research and development engineers in the automotive industry focus on improving the body, chassis, engine, electrical systems, drivetrain, safety and emissions control.
Since the mid-1920s, there has been a steady shift toward smaller, more economical cars that are designed with a greater emphasis on functionality and fuel efficiency. The popularity of the Model T, which was the first affordable automobile for the masses, led to a massive increase in the number of cars on the road. During this period, manufacturers often reduced options in order to keep costs down and compete effectively with the new competition. By the late twentieth century, the automobile had radically transformed the world’s societies and economies. Increasing concern over air pollution, energy consumption and global issues such as climate change have placed further demands on the automotive industry. This has led to the emergence of new automotive technology, including semiautonomous vehicles in which a computerized system either greatly aids or completely replaces the driver. This trend is expected to continue into the 21st century.