Automobiles, or automobiles for short, are vehicles that are driven by a motor powered by liquid fuel. The fuel is usually gasoline (petrol), but other fuels are used, such as diesel oil or liquefied petroleum gas (LPG). Automobiles have many uses, including personal transportation and commercial transportation. The most common type of automobile is the passenger car, which is designed to carry people. There are also sports cars, trucks, and SUVs that are designed to perform at high speeds on limited-access highway systems. In addition, there are buses and trolleybuses that are designed for mass transit purposes.

The scientific and technological building blocks for the automobile go back several hundred years, when Leonardo da Vinci created designs and models for transport vehicles. The automobile as a modern technology, however, was first perfected in Germany and France toward the end of the nineteenth century by men such as Karl Benz, Gottlieb Daimler, and Nicolaus Otto. The development of the internal combustion engine, which is now the most prevalent type of automobile power source, allowed manufacturers to build larger and faster cars.

Almost every household in America has one or more automobiles. Most of these vehicles are in regular use, logging more than three trillion miles each year. The automobile has become an integral part of American life, transforming the country into a global industrial powerhouse and making it possible for Americans to live anywhere in the world they desire.

Although the automobile has brought great freedom of movement to individual drivers, it has a number of drawbacks. It causes pollution, degrades landscapes, and encourages sprawl – straggling, low-density urban development that stretches out from the city center. It also increases the vulnerability of travelers to road hazards, such as dangerous drivers and inadequate road networks. It has even caused social distancing in some families, with children often living far from their parents.

The automobile has spawned industries devoted to its production, maintenance, and marketing. The assembly line developed by Henry Ford revolutionized industrial manufacturing, and the use of air-conditioned and upholstered seats has contributed to the comfort of automobile travel.

The automobile is a complex machine composed of thousands of parts that are arranged into semi-independent systems, much like the human body. The basic systems include the chassis, the bodywork, a drive system, and an engine that can be powered by gasoline, diesel, electric, or other sources of energy. A wide variety of engines are available, from simple 4-cylinder engines to sophisticated multi-cylinder engines that can produce more than 500 horsepower. The automobile has many other complex systems, such as the air conditioning, heating, and ventilation system, which are integrated into the basic drive system to provide maximum comfort. There are also many other features, such as the braking and suspension systems, that are used to improve safety, handling, and driving performance. The automobile industry is among the most sophisticated and technologically advanced in the world, and it is a major contributor to the economy of many countries.