Automakers are putting cars on a diet in a bid for better gas mileage.
They are finding ways to shave pounds from car bodies — from the hood to the back bumper — often by substituting plastic, composites and aluminum for steel.
When they use steel, it is often a higher-quality grade that delivers more strength and less weight.
Every 120-pound reduction can yield a 1% gain in gas mileage, says Bill Grabowski, director of body core engineering for Chrysler. Best of all, if engineers can make the body lighter, other components, such as brakes, suspension and the engine, can be lighter, too. And the vehicle won't need as much gas-guzzling horsepower to push it around.
Chrysler's new design computer can model automotive structures the same way that nature molds bodies. Just like the hollow bones of a bird that make it lighter for flight,