Automobiles, also known as motorcars or cars, are four-wheeled vehicles powered by an internal combustion engine. They are used to transport passengers and goods over land.
Originally designed to replace horse-drawn carriages, automobiles are the most common form of self-propelled vehicle in the world today. They are an essential part of modern society, allowing people to travel in and out of cities as well as between them.
Cars are made up of a variety of subsystems that perform specific design functions. These include the body, chassis, engines, drivetrain, controls, safety systems, and emission-control systems.
The most important component of an automobile is the engine, which powers the vehicle. Most engines are internal combustion engines using gasoline or diesel as fuel.
There are a few types of engine designs. The most popular type is a straight-line (inline) or radial.
A transmission is an important component of an automobile as it allows the driver to change gears easily. There are many different kinds of transmissions, which allow the vehicle to be operated at different speeds and torques.
The last main component of an automobile is the car body, which forms the shape and gives space for passengers and storage. Its design determines the aerodynamics and overall look of the vehicle.
The evolution of automobiles has been shaped by new inventions, air pollution regulations, safety legislation and competition between manufacturers. These developments have led to improvements in the body, chassis, engine, drivetrain, control systems, safety systems and emission-control systems of automobiles.