Automobiles (also called cars) are wheeled passenger vehicles with an engine that provides power for the vehicle. They are used primarily for personal transportation on land, but also for other types of transport.
The word “automobile” derives from the Greek words auto, which means “of itself,” and mobilis, which means “movable.” Similarly, “automobile” is sometimes used as an adjective to refer to vehicles that can move on their own without assistance, such as automatic transmission shift themselves or washing machines that automatically clean clothes.
Almost all automobiles use an internal combustion engine to turn the wheels and run. To do this, the pistons in the engine fire and the crankshaft spins, but it spins only within a narrow range, from very fast to very slow.
To turn the wheels, energy is sent from the engine through a transmission to the tires. The speed of the transmission determines how quickly the wheels turn.
Once the wheels are turned, they move the vehicle forward or backward depending on the direction that the engine is spinning. The tires and wheels form the only contact that an automobile has with the road surface, so they must be made of strong material that can withstand the roughness of the roads.
Although many people rely on public transportation to get around, owning your own car can save you money and help you stay on schedule. It’s also great for exploring new places and taking long drives on unplanned trips.