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Articles
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The motorcar
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History
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The modern automobile is a complex technical system employing subsystems with specific design functions. Some of these consist of thousands of component parts that have evolved from breakthroughs in existing technology or from new discoveries such as electronic computers, high-strength plastics, and new alloys of steel and nonferrous metals, as well as from factors such as air pollution, safety legislation, and foreign competition.
Passenger cars have emerged as the primary means of family transportation, with the total number in use worldwide expected to reach half a billion in the 1990s. One-third of these are in the United States, where more than 1.5 trillion miles are traveled each year. Approximately 500 different models have been offered annually to U.S. car buyers, about half domestic and half foreign in origin. New designs have been brought into the market more quickly in recent years than in the past to permit manufacturers to capitalize on their proprietary technological advances. With more than 30 million new units built each year worldwide, manufacturers have been able to split up the total into many very small segments that nonetheless remained economical to market.
New technical developments are recognized to be the key to successful competition. Research and development engineers and scientists have been employed by all automobile manufacturers and suppliers to improve the car body, chassis, engine, drivetrain, vehicle control systems, occupant safety, and environmental emissions, and further work by the industry is necessary to meet the needs of the 21st century.
Vehicle design depends to a large extent on its intended use. Automobiles for off-road use in countries that lack service facilities must be durable, simple systems with high resistance to severe overloads and extremes in operating conditions. Conversely, the customers for products that are intended for the high-speed, limited-access road systems in Europe and North America expect more passenger comfort options, increased engine performance, and optimized high-speed handling and vehicle stability. Stability depends principally on the distribution of weight between the front and rear wheels, the height of the centre of gravity and its position relative to the aerodynamic centre of pressure of the vehicle, suspension characteristics, and whether front or rear wheels are used for propulsion. Weight distribution depends principally on the location and size of the engine. The common practice of front-mounted engines exploits the stability that is more readily achieved with this layout. The development of aluminum engines and new manufacturing processes have, however, made it possible to locate the engine at the rear without necessarily compromising stability.
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History
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