But there are consequences to using lighter materials in today's passenger vehicles. Although the materials might be just as strong, they react differently in crash situations. By design, newer materials tend to crunch up and absorb the impact of a collision instead of channelling the impact through the metal to passengers inside the vehicle, O'Dell says. That means the physical damage to a vehicle made with today's materials could be more catastrophic, even if passengers are better protected from the impact.
"These parts are made collapse to absorb shock so they'll sustain more damage," O'Dell says. In older models, "you absorb the shock—that's the big difference," he adds.
While automakers have unveiled a slew of lighter, sleeker vehicles in Detroit this week, that doesn't mean hybrid and electric vehicles are out of fashion.
Carmakers understand that "they have to do both," Belzowski says. "You can't just do one or the other."