An automobile, also called a car, is a wheeled motor vehicle that is designed for transportation. Automobiles are most commonly powered by internal combustion engines, using gasoline (or other fuel) to create mechanical energy that turns the wheels of the car and moves it forward or backward. The energy of the engine is usually controlled by a transmission system that can vary the gear ratios to change the speed and torque output of the vehicle. Most modern automobiles have four wheels but some have three or more. Special automobiles include emergency vehicles like fire engines, ambulances and patrol cars.

The invention of the automobile greatly increased people’s mobility and freedom to travel long distances. It spawned new industries such as manufacturing and services such as hotels, restaurants and amusement parks. But automobiles can also cause harm to the environment through exhaust pollution and by destroying undeveloped land.

Automobiles are driven by internal combustion engines fueled with volatile inflammable liquids such as gasoline, petrol or kerosene and sometimes by electric motors. They use a transmission system to turn the engine’s mechanical power into the mechanical energy required to propel the car. The automotive industry has produced many different models of automobiles with varying features such as a retractable roof (in convertibles), different braking systems, and varied styling.

A modern automobile is usually designed with passenger comfort in mind and can seat up to eight passengers. The body of the car is typically constructed from steel or aluminum and may be painted in a variety of colors and finishes. The interior of the vehicle is typically upholstered with seats and instrument panels that can be adjusted to suit the driver’s needs. Many automobiles feature air conditioning and heating to keep the occupants comfortable in all weather conditions.

In the late 1800s, Karl Benz of Germany developed his first successful automobile. His design used a two-stroke internal combustion engine to produce mechanical energy for moving the car’s wheels. He also used a system to convert the engine’s waste products into fresh water and carbon dioxide.

The next step in automobile development was Siegfried Marcus of Austria, who built a crude automobile using a handcart chassis and a gasoline-powered two-stroke engine. This was the world’s first automobile to use a gasoline-powered internal combustion engine to drive its wheels. It was not as fast as a bicycle, and it had no seats or steering, but it represented a huge leap forward in automobile technology. Marcus’s crude automobile was later replaced by a more refined model that was capable of driving faster than a bicycle, and it became the prototype for modern automobiles. Several other inventors developed similar designs, including Nicolas-Joseph Cugnot of France and Francois Isaac de Rivaz of Switzerland. The automobile became widespread in the 1920s, when production techniques were improved and mass-produced models made them affordable for middle class families. By then, it was the most popular mode of transportation in the world.