Automobiles, the vehicles people use to transport themselves and their belongings, are among the most important inventions of the modern world. They have enabled a great deal of personal freedom and spawned numerous new industries, including road construction, fuel distribution, and parts manufacturing. Many people think of automobiles as an icon of the American Dream, a symbol of individual autonomy and freedom of action. However, the development of automobiles has been marked by a growing sense of conflict between the desire for freedom and the need to ensure safe, predictable travel conditions and to build appropriate infrastructure for a growing population.
The scientific and technical building blocks of the automobile date back several hundred years. The first self-propelled cars were steam, electric, or gasoline powered. Siegfried Marcus, a German in Vienna, is believed to have developed the first gasoline-powered engine in 1870, but his crude vehicle had no seats or steering. Karl Benz of Germany is widely recognized as the creator of the true modern motorcar in 1901, but he built only two cars from scratch and was unaware that Gottlieb Daimler was also working on an automobile at about the same time.
In the early 20th century, automobile production began to boom in the United States and Japan as manufacturers developed more efficient engines, improved chassis designs, and mass-production techniques. By the end of that era, it was impossible to imagine a modern life without an automobile.
A car’s basic design has remained fairly constant over the decades, although improvements have been made in materials and components and in the way the various systems work together. The most important systems are the engine, the power transmission system, the electrical system, the cooling and lubrication system, the wheels and tires, and the body.
Each of these major systems is arranged differently depending on the car’s configuration. For example, the engine may be located in front or rear, and the power-assist brakes (which help the driver stop and slow the car by turning some of the kinetic energy into electricity) may be integrated with the regular braking system or with the regenerative brakes.
Most modern automobiles have four to eight cylinders, which are arranged in two sets of three in the crankcase to create a smooth, continuous flow of air and fuel through the combustion process. The cylinders are connected by tubes that deliver the fuel and air to each cylinder for the combustion cycle.
The wheels and tires are attached to the chassis by a system of axles that provides traction and support for the car and helps absorb shock. The tires are designed to provide a good balance between high speed handling and long-distance comfort and safety. There are even specialized tires for off-roading and racing. The modern automobile contains many other small systems, such as air conditioning, stereo and sound systems, safety belts, and computerized control units. Those systems must be carefully integrated to make sure the vehicle functions smoothly and safely.