Graphic courtesy of GM.

Graphic courtesy of GM.

Cadillac is incorporating high-strength aluminum among the 13 different materials in its CT6 full-size sedan to save nearly 200 pounds of weight in a move to improve fuel efficiency, the company has announced.

The CT6 will debut March 31 at the New York International Auto Show and go into production later this year at General Motors' Detroit-Hamtramck assembly plant.

"With the CT6, we used high-strength aluminum, high-strength steels, and lightweight chassis components," said Johan de Nysschen, Cadillac's president. "We integrate aluminum and steel where it makes sense."

Using an advanced mixed-material approach for the lightweight body structure of the CT6 improves driving dynamics, fuel economy, and cabin quietness, according to Cadillac.

Aluminum makes up 64 percent of the CT6's body structure, including all exterior body panels. Using steel in those areas would have added 198 pounds.

The lower structure of the CT6 body is made up of 13 complex high-pressure die cast components, including aluminum sheets and extrusions. The vehicle underbody uses steel close-out panels on the lower structure to quiet the cabin without add weight from extensive sound-deadening materials.

A combination of aluminum spot welds, steel spot welds, flow drill screws, self-piercing rivets, laser welding, aluminum arc welding and hundreds of feet of structural adhesive are all used in assembling the body of the CT6.