Aluminum Cadillac weighs heavy on plant’s future

Michael Martinez
The Detroit News

General Motors Co. started delivering the new Cadillac CT6 sedan to dealers late last week, marking the end of a years-long transformation of its Detroit-Hamtramck Assembly Plant.

The CT6 is the first GM vehicle to have a body made mostly of aluminum — roughly 62 percent — which required a new, 180,000-square-foot body shop.

GM added roughly 205 robots to build the car, and the numerous new joining and welding techniques the car requires prompted training for the plant’s roughly 1,400 workers. Another 1,200 new workers are being trained to start working on a second shift in May to produce the CT6 along with the rest of the Detroit-Hamtramck lineup.

“Even though you’re an expert, you have to go back and start again,” said Gary West, plant manager. “That’s what they were challenged to do with this car. Everybody had to look at themselves and grow.”

The CT6 uses five new joining techniques: patented aluminum spot welding technology; aluminum laser welding, which creates seamless exterior panels; self-piercing rivets, which join different types of materials together with a clean appearance; and flow drill screws, which join different types or materials and are used with adhesive.

Virtually all of the car’s front and rear is made of aluminum, while GM chose to keep using steel for the car’s cabin for safety and noise reasons. The result is a sedan that uses fewer body parts and weighs about the same as the much-smaller Cadillac CTS, despite being eight inches longer.

“It translates to the customer getting better fuel economy,” said Lyndon Lie, chief engineer of the CT6.

The CT6 can get up to 31 miles per gallon on the highway and up to 22 mpg in the city with its 2-liter turbocharged four-cylinder engine.

All the new equipment was installed and worker training began about a year ago, according to Rob Bucchi, a shift leader for the new body shop. Since the space was new — it had been used to store materials — workers were able to continue to build the plant’s other vehicles: the Chevrolet Volt plug-in hybrid electric vehicle, Chevrolet Impala, Chevrolet Malibu and Cadillac ELR.

The plant will add production of a new Buick LaCrosse this summer, GM said.

The Detroit automaker has invested over $1 billion in Detroit-Hamtramck during the last five years, including a $384 million investment in April 2014 for new body shop tooling, equipment and additional upgrades to build the next-generation Volt, CT6 and the all-new 2017 Buick LaCrosse. It’s unclear how much of that money went specifically to the CT6 body shop.

The plant produces about 45 vehicles an hour, West said. That number will double when the second shift starts.

‘An awesome history’

“This plant has an awesome history of cars, and we’re looking forward to what this car can do for us,” West said. “It’s all new materials and all new body shop ... I’m excited to see how the market accepts it.”

The CT6 was designed for the Chinese market and is meant to be a direct competitor to the Mercedes-Benz E-Class, the BMW 5 Series and the Audi A6.

“It is the top-of-the-line car for Cadillac,” Lie said. “For now, it’s our flagship car and, we think, is setting the standard for American luxury.”

The vehicle comes in four trim levels and includes an industry-first, 360-degree exterior video recording system and a rear camera that streams high-resolution video to the rear view mirror to expand visibility for drivers. Other features include seats with five massage programs and Cadillac’s first Bose Panaray audio system with 34 speakers and rear-seat infotainment system.

It includes three engine options: a 2-liter, turbocharged four-cylinder; 3.6-liter V-6 and new 3-liter V-6 twin-turbo engine that will generate an estimated 400 horsepower. The engines are paired with eight-speed transmissions. It’s available in rear-wheel drive or with on-demand all-wheel drive.

Being marketed globally

In addition to the U.S. and China, the CT6 also will be sold in Europe, Korea, Japan, Israel and the Middle East, with vehicles exported beginning in early 2016 for those markets from Detroit-Hamtramck. The car is being built in Shanghai for the Chinese market.

The five-passenger car is one of eight new vehicles Cadillac plans to launch by the end of the decade as part of a $12 billion infusion to expand Cadillac. The CT6 starts at $54,490.

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