Automobiles are self-propelled vehicles for transporting people and cargo. They have four to eight tires and are powered by an internal combustion engine or electric motor. Automobiles are the main form of transport for most people in the world. They are a major source of pollution, but also make possible such luxuries as long distance travel and the flexible distribution of goods. They have restructured society, allowing for the creation of industries such as tourism and leisure activities. The automobile is one of the most important inventions in history.
The word “automobile” comes from French for car (as in carriage) and mobile (as in wheeled). The automobile has radically changed the way we live, work, and play. Its design and operation are the subject of much research and development. The branches of engineering that focus on the design, manufacture, and technology of the automobile are known as automotive engineering.
The basic systems of an automobile are the engine, fuel system, transmission, electrical system, cooling and lubrication system, and chassis, including suspension and braking systems. The chassis and body, analogous to the skeletal structure in a human being, support these systems. The chassis also provides safety, comfort and convenience features for the passengers.
The specific design of an automobile depends on its intended use. For example, a vehicle designed for off-road driving needs durable, simple systems with high resistance to extreme overloads and operating conditions. On the other hand, an automobile designed for highway cruising must provide passenger comfort options and optimized high-speed handling and stability.