The economics of materials selection

Cost per pound of reduced vehicle mass is helping to drive innovation in steel, aluminum and carbon composites.

“We've entered an era where true weight reductions in vehicles are occurring,” noted Dr. Alan Taub, professor of Material Science & Engineering at the University of Michigan. “There is no new vehicle launch that doesn't talk about a 5-10 percent reduction in curb weight because it's now clearly a part of fuel economy. And while the gains are still coming from powertrain improvements and the introduction of partial and full electrification, about 15 percent of fuel-economy improvements today come from vehicle weight reduction.” His rule of thumb: Decreasing vehicle weight by 10% yields a 6% improvement in fuel economy.

At the 2019 Society of Plastics Engineers' ANTEC conference, Dr. Taub, formerly GM's head of R&D, presented a review of the three major materials groups-steel, aluminum, and composites-that he expects will predominate in vehicle body structures (increasingly in a mixed-materials play) going forward.