Automobiles have become the main means of transportation for individuals and families. There are over 1.4 billion passenger cars worldwide, with about one-fourth produced in the United States. In the United States alone, Americans drive about three trillion miles a year. Most of these vehicles are made by foreign manufacturers, but American car companies are introducing new designs more frequently. Globally, about 70 million new passenger cars are produced each year.
Automobiles can be either electric or fuel-powered. There are many types of motorcycles. Some motorcycles are electric, while others are powered by gas. Motorcycles use four to six-speed transmissions. They can also tow trailers. Motorbikes have a chain or belt system that transfers power to the wheels. Motorcycles have brakes for the front and rear wheels, operated by the throttle, handgrip or foot pedal. Motorcycles are more fuel-efficient than automobiles, averaging more miles per liter. This is advantageous to countries where oil prices are rising.
Some people confuse motorcycles with automobiles. Motorcycles are not automobiles, because they cannot carry a large number of people. In addition, motorcycles have three wheels instead of four. And a side car makes them more like an automobile.