Study opens the door for major auto weight savings

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Magna Interior Inc. In addition to its lighter weight, the proposed new door module can be installed easily on the assembly line and can also be taken apart and repaired quickly.

Detroit — Plenty of individual suppliers have proposed ways to reduce the weight of car doors — trimming ounces by swapping out nylon for steel in window regulators, making a more efficient interior trim or lighter closures.

But a new development backed by FCA US LLC, Magna International Inc., Grupo Antolin and the U.S. Department of Energy took a holistic approach by looking at a door as a complete system that could integrate everything available on the market today. The result is a door that cuts weight by 42.5 percent, without a dramatic increase in cost.

“It’s leveraging existing technology, which is key to keeping development costs down,” said Ian Simmons, vice president of business development for Magna during a Jan. 9 press event at the North American International Auto Show in Detroit. “This is fresh eyes and a new look at how you would do a door program today as a complete solution.”

A lighter weight interior trim contributed to 7 percent of the overall weight savings, he said, while using aluminum in place of steel for the outer panels also dropped pounds.

The module represents a weight improvement available in the near term, even as other government and industry consortiums continue investigating long-term lightweight moves, such as bringing more composites and carbon fiber onto the car, said Reuben Sarkar, deputy assistant secretary for transportation with the Department of Energy, which also supports the Institute for Advanced Composites Manufacturing Innovation.

“Normally, [weight reduction programs] are broken down into individual components. You get a couple of marginal pounds out of it here and there, but not 42 percent,” he said.

The lightweight door module study makes some material substitutions, but it doesn’t expect the auto industry to jump quickly into using completely new materials for their standard production, such as composites. Instead, everything in the study is available on the market now, Simmons said.

The U.S. government has set a target to reduce vehicle weight by 25 percent to improve fuel economy. Other governments around the globe have their own sustainability targets related to fuel and emission improvements which rely on lighter vehicles. Even with the pending presidential change in Washington, automakers are still looking for ways to cut mass.

Cutting 42 percent out of the doors wouldn’t get automakers to the 25 percent target on the whole vehicle, Sarkar said, but, “It’ll make a significant dent in it.”

While FCA participated in the project, the findings are available to all automakers, not just Fiat and Chrysler.

Doors are a good focus for the study because they are easy to focus on as an individual system, and the type of doors used in the new study are used on 70 percent of vehicles on the market, Simmons said.

In addition to its lighter weight, the proposed new door module can be installed easily on the assembly line and can also be taken apart and repaired quickly.

“It’s met all the simulation targets, all the safety and functional objectives, so we’re going through the final prototype testing,” Simmons said.

Magna is introducing the module to automakers now, in hopes that it can find a home on a future model year vehicle.