Steel, aluminum and composite makers are vying to get more of their materials into cars and trucks. By Jim Ostroff, Associate Editor June 22, 2010 The next car you buy will probably be lighter, courtesy of federal mandates to increase average gas mileage by 30% to 40% over the next five years. Automakers figure the easiest and cheapest way to cut fuel consumption is to make passenger cars, which now weigh about 3,500 pounds on average, about 400 pounds lighter.Under Uncle Sam’s new rules, the current 27.5 miles per gallon minimum for passenger cars will jump to 33.8 mpg for 2012 models and 39.5 mpg for 2016 models. A similar phased-in approach for light trucks will require them to average 29.8 mpg for 2016 models. The upshot: Heated competition between steel and aluminum manufacturers for a larger slice of the lucrative pie. Aluminum makers have a weighty advantage and are aiming to use it to muscle out steel for use in vehicle roofs and other body panels, engines and structural components. Manufacturers such as Alcoa, Rio Tinto Alcan and Novelis are developing aluminum products with greater strength to better stand up to the everyday dings that cars pick up in parking lots and elsewhere, as well as specialty versions for use in bumpers that crumple to absorb the force of a collision. The aluminum industry is honing its strategy to win a large chunk of the plug-in electric car market that will take off within five years. Advertisement Steelmakers are fighting back with a lighter generation of high-strength steel. Thanks to research stretching back 20 years, automotive steel today weighs around 25% less than it did during the heyday of muscle cars in the 1960s and 1970s. Automakers including Ford routinely use this steel in key structural components in auto body pillars and panels. Now steelmakers are on the cusp of commercializing a breakthrough product that is not only 10% lighter yet, but stronger and more easily molded. “This third-generation product will enable us to make auto parts that are much lighter than today because the steel can be made thinner with no compromise in strength,” says Ronald Krupitzer, a vice president for automotive applications with the American Iron and Steel Institute, a trade group. Down the road, look for steel and aluminum to be challenged by an even-lighter-weight contender -- composite carbon fiber. Long used in aerospace and for pricey bicycles and tennis rackets, the pricey material has been finding its way into exotic cars such as Chevrolet’s Corvette ZR-1. Odds are the price differential between carbon fiber and aluminum and steel will narrow by decade’s end, thanks in part to research and development at the Department of Energy’s laboratory in Oak Ridge, Tenn., and at Magna International, Canada’s largest automotive parts supplier.