Automobiles are vehicles that use internal combustion engines powered by volatile fuels. They are the dominant means of transportation worldwide. In the United States alone, they are used for more than three trillion kilometers (five trillion miles) per year. Passenger cars account for the vast majority of automobiles in operation, with over 1.4 billion cars currently on the road. The automobile industry continues to evolve, with new technology being incorporated into the body, chassis, engine, drivetrain, control systems, and safety systems of modern cars.
Exactly who invented the modern automobile is the subject of ongoing debate. However, many inventors contributed to the development of the automobile, including Joseph Cugnot, who crashed his steam-powered “Fardier” into a wall in 1771, Siegfried Marcus, who designed a two-stroke engine using gasoline in 1870, and Karl Benz, who developed a four-stroke gas-powered Benz Patent-Motorwagen in 1885 or 1886.
The modern automobile has evolved into an advanced technical system consisting of a wide variety of subsystems and thousands of component parts that have been designed to work together in harmony. The most important parts are the internal combustion engine and the transmission.
The internal combustion engine is a complex machine, and its performance depends on several factors, such as the type of fuel, the compression ratio, and the design and construction of the car’s air intake and exhaust systems. In addition, the engine’s power output is related to the distribution of weight and the aerodynamic center of pressure.