Automobiles are motor vehicles that have four wheels and carry a driver and passengers. They are usually powered by internal combustion engines, although electric motors and some other kinds of engines are also used. The word “automobile” is derived from the Latin words for “self-moving carriage.” The first automobiles were steam or electricity-powered, but gas and oil-powered cars became more common after 1900. The automobile revolutionized the world, giving people freedom to travel and visit places that had previously been inaccessible or impractical. It also brought changes in lifestyle, leisure activities, industry and services.

Automakers focus on three areas when designing and manufacturing their cars: safety, performance and economy. They must ensure the car is safe to drive, has good road handling and visibility, and a comfortable ride. A good design is also important to make the car attractive to consumers. The automobile must also be economical to produce and operate, especially in terms of fuel consumption. Various factors affect the design of a vehicle, including its price, size and weight. It must be able to accommodate different types of drivers, and offer a range of powertrains that can meet varying consumer demands.

Initially, automobiles were mostly for the wealthy because they were expensive and difficult to operate. Karl Benz, a German engineer, is credited with inventing the first gasoline-powered automobile around 1885. Other inventors and engineers followed with their own designs. But it was Henry Ford who revolutionized the automobile industry with his assembly line and Model T, allowing the automobile to become more affordable for average Americans.

The modern automobile has many parts, but the most important is its engine and transmission. The engine converts chemical energy from the fuel into mechanical energy that turns the wheels. The speed at which the wheel turn is called torque, and how much energy it has is called horsepower.

An automobile must also have a chassis, bodywork, control system, electrical equipment and service devices. Its fuel can be gasoline, diesel, natural gas, hydrogen or battery electricity. Other fuels such as liquefied petroleum gas (LPG), biodiesel or ethanol are also being investigated for use as an alternative to gasoline.

Automobiles may cause problems if too many of them are driven in the same place at the same time. Traffic congestion slows them down, and the exhaust from gasoline-powered cars contributes to air pollution. The dwindling world oil supplies has made automobiles less desirable in some countries, which have moved to more environmentally friendly forms of transportation.

While it is true that an automobile can be dangerous if it is operated by reckless or drunk drivers, it also offers many benefits. Owning a car saves you the time it would take to wait for a bus or taxi, and it lets you spend more of your time doing the things you like. It can also help you save money on gas and parking. You can also use your own car to take you to school or work, and to go shopping and visiting friends.