Automobiles are complex technical systems that consist of numerous subsystems with specific design functions. These systems range from those that provide cooling and lubrication, to those that control the engine’s operation and deliver power to the wheels. In addition, the automobile requires a system for delivering fuel, and a chassis that supports the engine, steering, suspension, brakes, wheels, and tires.
The automobile has dramatically altered modern life. Entire societies have been reorganized around the power of rapid, long-distance movement conferred by automobiles and around the flexible distribution of goods made possible by trucks. However, the freedom of movement automobiles make possible also encourages sprawl (i.e., straggling, low-density urban development), which degrades landscapes and produces traffic congestion that tends to immobilize the very automobiles that allow sprawl to continue.
While the precise date of the first automobile is a matter of contention, the history of its development is relatively well established. The earliest automobiles used steam, electric power, or battery-powered engines. In the late 1600s, Leonardo da Vinci produced a number of designs and models for transport vehicles, and in the early 1800s, Francois Isaac de Rivaz, Siegfried Marcus, and others developed prototypes powered by internal combustion engines that burned kerosene or hydrogen gas.
In 1883, Edouard Delamare-Deboutteville and Leon Malandin of France fitted a four-stroke liquid-fueled internal combustion engine to an old horse cart. During the vehicle’s first test drive, the tank hose came loose, causing an explosion. The vehicle was destroyed, but the two men patented their work, which contained several innovations that would not be widely adopted for decades.
Gottlieb Daimler, a German, then improved the engine, modifying it to run on gasoline and developing an ignition system that avoided the explosions associated with earlier engines. By 1888 or so, he had built the first true automobile, with seats, a steering wheel, and a brake pedal. He may have built as many as thirty vehicles in this period, with various improvements.
An automobile’s power is transmitted from the engine to the wheels through a transmission system, which can have one, two, or three gears. Each gear provides a different ratio of the crankshaft’s revolutions per minute, which produce torque, to the number of axles turning the tires. This is called the power to weight ratio.
The suspension system of an automobile consists of springs that support the chassis, and shock absorbers, which dampen or quiet the motion of the springs by absorbing vibrations caused by uneven road surfaces and other disturbances. The wheels and tires are supported by a system of springs that allows them to adapt to changing road conditions. The braking system of an automobile consists of a frictional braking unit that acts to slow the automobile down when the brake is applied. The wheels and tires are also steered by a steering mechanism.