Automobiles are motor vehicles that use their own wheels to transport people and freight. The word “automobile” derives from the Greek words “auto” (self) and “mobilis” (“moving”). Unlike horse-drawn carriages, which were powered by horses, modern automobiles are powered by engines that convert gasoline or other fuel into energy to move the vehicle and power electrical systems. There are more than 1.2 billion cars in operation worldwide. The automobile has revolutionized lifestyles, changing where people live, work and shop. It has become the primary means of family transportation in many countries. The automobile has also changed the way people travel, providing speed and flexibility compared to other forms of transportation such as trains or planes. The automotive industry is a large component of most economies and supports millions of jobs worldwide in the manufacture, maintenance and repair of automobiles and other car-related products.
Invented and perfected in the late 19th century, the automobile is a complex machine with hundreds of mechanical parts. The automobile is powered by an internal-combustion engine that obtains its energy from the expansion of gases, and most modern cars use gasoline as their fuel. The gas is burned in a small combustion chamber, which generates power that turns the crankshaft to drive the car’s wheels. The engine’s output may be transmitted by a conventional transmission system or an automatic transmission, which can shift gears to vary the car’s speed and torque.
The automobile revolutionized urban life, causing people to move from rural areas to cities for work and leisure. In addition, it has changed how we build homes, grow food, travel, seek recreation and conduct business. It has spawned ancillary industries such as steel, aluminum and petroleum. It has also contributed to the development of the consumer-goods economy and has influenced public policy, including land-use decisions.
In the 1920s, automobile production became a powerful force that brought major changes to society. The industry ranked first in value of product and provided one of every six jobs in the United States. It fueled the growth of a new consumer-goods-oriented economy, and its demand for petroleum and other industrial products drove technological advances in the steel, oil and rubber industries.
By the 1930s, market saturation and technological stagnation combined to slow the rate of automobile production. During World War II, manufacturers diverted most of their production to military needs. By the end of the war, the Big Three (Ford, GM and Chrysler) made seventy-five essential military items, amounting to more than one-fifth of the nation’s total war production.
After the war, sales of automobiles recovered quickly. However, by the turn of the 21st century, questions about ‘gas-guzzling’ automobiles and concerns over pollution and draining of the world oil supply made many Americans seek smaller, more fuel efficient vehicles. Manufacturers responded with SUVs, crossovers and cars that run on electric or hybrid motors. They also redesigned the body, chassis and engine to make them lighter, more functionally designed and safer.