MIXING METALS

Cadillac pursues aluminum/steel mix for new CT6 luxury sedan, leading to advances in body assembly.

Next fall, Cadillac's new top-of-the-line model, the CT6 sedan, rolls out of General Motors' big Detroit-Hamtramck assembly plant and onto dealership sales floors nationwide to confront the likes of the Mercedes S-Class, Audi A8, and BMW 7 Series in the premium luxury large-car market.

To equip its flagship sedan for the challenge, Cadillac designers and engineers have built the CT6 on a unique vehicle architecture, an aluminum-intensive body structure that is fully one-third steel. Twenty-one patents are pending for the new full-size, rear-wheel-drive, transverse-engine configuration, a variation of GM's Omega II platform.