Automobiles are wheeled vehicles designed primarily to run on roads and carry passengers instead of cargo. Most definitions of automobiles are based on the use of internal combustion engines that burn fuel to create mechanical energy for propulsion. Modern cars can contain many subsystems, and the design of each is influenced by factors such as performance goals, market demands, production costs, passenger comfort, and safety.
Few inventions have had as great an impact on the world as the automobile. It has dramatically changed the lifestyles of people around the globe, and opened up a world of possibilities for careers, families, and travel. Having an automobile provides a feeling of independence and freedom that is unparalleled. Whether you are going on a long road trip or visiting family, a car can make the journey easier.
A car is a complex technical system with thousands of components. Some of these are essential for the operation and safe operation of the vehicle, while others provide useful or convenience features to the passengers. For example, safety belts and laws requiring their use have significantly reduced deaths and injuries. Other innovations, such as airbags and specialised child restraint systems, have enhanced passenger safety.
The earliest automobiles were powered by steam, electricity, or gasoline. Gasoline internal combustion engines achieved dominance in the 1910s. In 1885 Karl Benz built the first petrol powered automobile, which was able to travel for more than 106 km (about 65 miles). In Germany, a holiday is celebrated to mark the anniversary of the event.
Most modern cars are designed to be flexible, capable of operating under a variety of conditions and driving situations. This flexibility is accomplished by varying the performance of individual automotive components, and by combining multiple systems. For example, front-wheel drive allows for a smaller engine and better fuel efficiency, while independent suspension improves handling and ride quality. The choice of engine and its arrangement, the type of fuel, and other factors influence the power, speed, and economy of an automobile.
The skeletal structure of an automobile is called the chassis. It is the frame that supports the other automotive components, including the wheels, steering, and braking systems. The chassis must be strong enough to support the weight of the car and to withstand the shocks and tension of driving, but it must also be flexible. The body is the outer layer that protects passengers, offers storage space, and houses the various automotive systems. The body must be light to reduce the overall weight of the car, yet rigid enough to support its parts and withstand the force of an accident. The body is sometimes made from a single piece of metal or welded steel, but it is more often made of plastic or fibreglass. The body also has important structural functions, such as providing a crumple zone in a crash and keeping out the elements. The design of the body must be compatible with other automotive components, to ensure their correct functioning and maximum safety.