BACKGROUND: Porsche's Carrera GT carries a $440,795 price tag, but that's not the only special feature that makes it a high-end niche model. It is also composed entirely of plastic hybrid materials, meeting industry standards while improving on safety, body strength, and load-bearing capability. It's the latest development in an ongoing effort to incorporate more lightweight plastic materials into the automotive industry, along with other energy-efficient technologies such as fuel cells and hybrid power systems.
HOW FUEL CELLS WORK: Much like a battery, a fuel cell draws energy from chemical reactions. Specifically, it converts hydrogen and oxygen into water, producing electricity in the process. This can then be used to power motors, lights, or electrical appliances. Chemicals constantly flow into the fuel cell, so it never goes dead. If a fuel cell is powered with pure hydrogen, it will convert 80 percent of its energy into electricity, so it is a very attractive option for automotive manufacturers seeking better fuel efficiencies. A standard gasoline-powered car isn't very energy efficient: only about 20 percent of the content of the gas is converted into usable energy. However, hydrogen is difficult to store, so most fuel cell prototypes convert methanol into hydrogen as an initial step. This reduces overall efficiency to 30 percent-40 percent.
WHAT ARE HYBRIDS: Gasoline-powered cars are the most common type, and there are some battery-powered electric cars available today. A hybrid vehicle is a combination of the two, attempting to reap the best of both approaches. For example, the Honda Insight has a gasoline engine to provide most of the car's power, in combination with an electric motor to add extra power as needed for acceleration. The electric motor can double as a generator while braking and only has to run part of the time. One disadvantage is that the gasoline engine must therefore run at varying speeds, which reduces its energy efficiency.
WHAT IS CAD: A computer-aided design system combines hardware and software to enable the user to design everything from furniture to cars and airplanes. The user can view a design from any angle and zoom in or out for close-up or long-distance views. CAD systems typically rely on a combination of a keyboard and conventional mouse to control what's on the screen.