The trend has automakers introducing lighter vehicles and embarking on demonstration projects designed to carve hundreds of kilograms off their most popular vehicles. Last month, for example, GM received major awards for its new Cadillac ATS sedan that weighs 3,315 pounds (1503.7 kilograms), making it one of the lightest vehicles in its class, thanks in large part to an all-aluminium hood, magnesium engine mounts, and other lightweight materials.
"Every automaker we talk to is talking about how they can do more "˜lightweighting,' " says Patrick Davis, vehicle technologies program manager at the U.S. Department of Energy's Vehicle Technologies Office.
As they contemplate the new fuel standards, which require cars to have an average miles-per-gallon rating of 54.5, automakers cannot rely on consumers to buy more hybrid or electric cars, or smaller, more efficient models.
Reducing the weight of conventional cars offers a way to guarantee better fuel efficiency: every 10-percent reduction in weight provides a 6- to 7-percent improvement in fuel economy. Weight savings can lead to further fuel economy improvements by allowing automakers to use smaller, lighter engines and other components. Davis says the DOE's hope is that all cars will be 35 percent lighter by 2025.
