Automobiles are motor vehicles that can move on the ground under their own power and are intended to transport passengers. Vehicles can be of any size or shape and can be powered by a variety of sources, such as an internal combustion engine, diesel engines, or electric motors.
In general, automobiles are designed to satisfy a range of different functions and conditions that include safety, environmental control, and performance. Various features such as the design of the body, suspension characteristics, and braking systems, for example, affect these requirements.
The design of an automobile must take into account a wide range of factors, and compromises are often made to achieve as much as possible from each system. For example, an automobile’s suspension system is likely to need to be durable enough for off-road use yet flexible enough for high-speed, limited-access road systems.
An automobile’s design also must consider its fuel economy and its emissions controls. These aspects have become increasingly important in recent years as governments have made environmental regulations a central part of determining car standards.
Despite the many technological advances, the basic structure of an automobile remains essentially the same: an engine powered by fuel, and wheels for propulsion. Some automobiles, however, are now designed to have multiple power sources.
Since the 1920s mass production techniques have greatly reduced the costs of automobile manufacture, placing reliable and safe cars within the reach of the middle class. Ford’s perfected assembly line, for example, helped to shift manufacturing from a few large industrial plants to a diversified network of small factories and distribution centers. It also created a new group of semiskilled workers with remunerative industrial employment and increased the purchasing power of America’s middle class.