Carbon fiber truck bed ‘aggressive stance' for GM

Traverse City, Mich. — General Motors Co. drew attention last year when it announced the option for a carbon fiber pickup box on the GMC Sierra.

The application of the high-cost, high-strength thermoplastic material on the truck bed was a first for the automotive industry, which typically recites a "cost is king" mantra.

Mike Siwajek, vice president of research and development at Continental Structural Plastics Inc., the composites supplier that molds and manufactures the CarbonPro box at its facility in Huntington, Ind., said that's not going to be the case for every vehicle or every model.

"GM has taken an aggressive stance on that, and said this is something that brings value," Siwajek said during an Aug. 6 session at the Center for Automotive Research's Management Briefing Seminars. "It brings lightweight. It brings durability. And it's a really, really fantastic project."

You have to determine where carbon fiber, which carries a price tag anywhere from $6-$40 per pound on average, provides the most value, he said.

"From our standpoint, you don't want to go in and say, we're just going to put carbon fiber there just for the sake of putting carbon fiber," Siwajek added. "Yes, it saves weight. Yes, it's high strength. … Where does it bring the most value for the customer?"

For GM, the strategic use of carbon fiber, plastics and other materials such as steel, aluminum and glass fiber composite on the Sierra enabled a mass savings of 62 pounds. It also eliminated the need for paint or a bed liner, which saved an additional 40 pounds of mass.

The CarbonPro box was a runner-up in the module category for the 2019 Enlighten Award from global technology firm Altair Engineering Inc. The application marked a paradigm shift for carbon fiber composite use in the automotive industry and could open the door to wider adoption of the material in high-volume manufacturing of structural parts.

But when it comes to performance, mass reduction and materials — whether it's steel, aluminum, plastics or attention-grabbing carbon fiber — Siwajek said automakers just "want solutions to their challenges," and they want that solution to bring value and be cost-competitive.

"At the end of the day, I don't know that anybody wants to pay for weight. They want value for performance," he said. "So you try to figure out where it fits best, and it's different from case to case."