Automobiles, also called motorcars or cars, are four-wheeled vehicles used primarily for transportation. They are propelled by internal-combustion engines using volatile fuel and are typically operated by the driver with a steering wheel, throttle, and brake pedals. Automobiles have numerous subsystems that must be designed and coordinated to work together. These systems include the engine, transmission, cooling system, electrical system, braking system, wheels and tires, and the body. The automobile has been an important force for change in twentieth century societies. It has transformed urban life and restructured the distribution of goods by making long-distance travel affordable. It has revolutionized ancillary industries, especially steel and petroleum, and made possible a new consumer goods-oriented society.

The development of the automobile was a remarkable technical achievement. It was conceived in the late nineteenth century and redeveloped over several decades. In the early 1920s, Henry Ford innovated mass production techniques, transforming the industry from one-man shops to large, publicly traded corporations.

In the United States, Ford, General Motors, and Chrysler became the “Big Three,” dominating the automotive market for most of the first half of the 20th century. But by the late 1980s, automobile manufacturing shifted from the United States to Japan and elsewhere in the world.

The automobile has become an integral part of modern society and continues to exert a significant influence on the world economy. In addition to providing personal mobility, it is a major employer and the largest customer of many industrial products. It has influenced the design of cities and other infrastructure and the layout of suburban areas. It is a major consumer of petroleum and is the leading buyer of steel and other metals. It has stimulated a number of ancillary industries, including the manufacture of tires, batteries, and paint.

As anyone who owns a car can attest, the automobile has greatly improved quality of life. Time spent traveling from one place to another is greatly reduced, allowing people to spend more time doing the things they enjoy most. Moreover, emergencies are more easily managed when an automobile is readily available. For instance, if a child is sick or if an accident occurs, having a vehicle at hand allows individuals to arrive at the scene faster than would be possible with public transportation. As a result, the automobile has been credited with reducing stress and anxiety. Moreover, the convenience and flexibility offered by automobiles has allowed families to bond together in ways that would not have been possible without them.