Automobiles are powered by a fuel (typically gasoline or other petroleum-based liquids) that is burned to make the internal combustion engine run. The engine sends energy to the wheels through a transmission that has gears that can make the car go faster or slower. The speed of the wheels is controlled by the amount of power sent from the engine, which is usually measured in kilowatts or horsepower.
The automobile has been a major force for change in twentieth-century life in the United States. It has revolutionized transportation, spawned many ancillary industries such as steel, petroleum and auto parts and is one of the largest consumers of energy. It has fueled economic growth and created a new consumer culture. It has also facilitated suburbanization and has spurred the development of new industries, such as service stations, hotels and motels. The automobile has ended rural isolation and brought urban amenities—including education, medical care and shopping opportunities—to rural America.
Although the first modern motor cars were perfected in Germany and France in the late nineteenth century by Gottlieb Daimler, Karl Benz, Emile Levassor, Nicolaus Otto and Wilhelm Maybach, it was Henry Ford who put automobiles within reach of the average American by using mass production techniques to build his Model T. This was the first car that could be considered a true “motorcar” in that it had enough features to be described as such, but was still affordable to most people.
Into the 1960s engineering was subordinated to the questionable aesthetics of nonfunctional styling, and quality declined significantly. By the 1970s concerns over air pollution and dwindling world oil supplies made American cars less desirable, and they lost market share to fuel-efficient, functionally designed, well-built small cars from Japan.