Automobiles are one of the most universal of modern technologies. They are four-wheeled vehicles used for passenger transportation and powered by internal combustion engines fueled most often by gasoline, a liquid petroleum product. Automobiles are manufactured by one of the world’s largest industries, with more than 73 million cars produced worldwide in 2017. The automobile revolutionized our lives by giving us more freedom and access to jobs, places to live, and leisure activities. However, it has also brought about changes to the environment and society. Industries and services have developed to provide fuel and parts for automobiles, and highway rules and laws have been established to ensure safety.
Most automobiles run on an internal-combustion engine, and their power is transmitted to the wheels by a transmission system. The transmission system has a set of gears that can change the ratio between engine speed and the amount of power applied to the wheels. The transmission systems of most automobiles have been designed to operate with gasoline, but there are also electric and other fuel-powered automobiles.
The automobile was first conceived of as a device for transporting goods. The earliest known self-propelled vehicles were steam engines attached to wagons, but these were slow and difficult to control. Automobiles became more popular as a means of transport after the introduction of the Model T by Henry Ford, who used the assembly line to make them affordable for most people. By 1920, cars had become the dominant form of passenger transportation in the United States and most other countries.
Among the most important developments in automobile technology have been the improvements of the internal-combustion engine and transmission system. The internal-combustion engine, in particular, was revolutionized by the development of high-strength plastics and alloys of iron and nonferrous metals. These materials have enabled a substantial increase in the power and efficiency of automobiles. In addition to the engine, other significant improvements have been made in the chassis and drivetrain of automobiles. These include the use of independent suspension, four-wheel brakes, and regenerative braking systems (which turn the energy of a car’s motion into electricity that can recharge its batteries).
While Siegfried Marcus developed the first gas-powered engine, Karl Benz is considered the father of the modern automobile. He patented his Benz Patent-Motorwagen in 1886, and began selling them commercially in Germany the next year. The most recent innovation in the automobile has been in the area of safety and security. This has been the result of the increasing number of air bags and other passive safety devices. There have also been advances in the ability to detect and respond to a wide variety of crash scenarios, and the development of computerized systems to assist drivers and to monitor vehicle functions.
Automobiles continue to be an important part of our lives, and will probably be so for many years to come. They have many advantages over other forms of transportation, such as trains and planes, including the ability to travel long distances quickly and in relative comfort. They have allowed individuals to travel independently of friends and family, and they allow them to visit distant locations that would be difficult or impossible to reach on foot.