Caddy V-6 to debut in CT6

Melissa Burden and Henry Payne
The Detroit News

Cadillac's new CT6 power player will debut a powerful new V-6.

General Motors Co. said Friday it will roll out new V-6 engines for the Cadillac lineup, including a best-in-segment, 400 horsepower, 3-liter twin turbo V-6 that will debut with the luxury brand's upcoming CT6 flagship sedan.

The automaker said the next generation of V-6 engines also includes a new, 3.6-liter naturally-aspirated engine that will be shared by the CT6, midsize CTS, and compact ATS sedans. The CT6 introduces a compact, new 8-speed transmission for the 3.6-liter V-6 that is the same size as the outgoing 6-speed transmission. The V-6 powertrains are part of GM's massive, $12 billion investment in its luxury brand.

"Cadillac is investing heavily into expanding our portfolio with eight new products by 2020," Cadillac Chief Engineer David Leone said. "It will be in five of those segments for the first time, which require Cadillac to develop a much wider range of powertrain."

The engine announcement is coordinated with the first new product in that rollout, the CT6 large sedan, which was teased in an Oscars ad in February. The Detroit automaker will reveal the CT6 during a March 31 event in Brooklyn ahead of press days at the New York International Auto Show. Cadillac confirmed that the CT6 will feature an engine lineup of a turbocharged, 2-liter four-cylinder (also used in the CTS), new 3.6-liter V-6, and the twin-turbo V-6. The top-of-the-range Cadillac will be built beginning late this year at GM's Detroit-Hamtramck Assembly Plant.

"A new premium engine with a new premium car is just what the luxury space needs," said Stephanie Brinley, an auto analyst with IHS Automotive. "It's a smart move for Cadillac to offer a brand new engine in a car that promises premium content and technology."

Cadillac has used a 3.6-liter V-6 across many vehicles over the years, but the latest engines are 99 percent new, sharing only two small parts from the previous generation. Cadillac said the twin-turbo V-6 and 3.6-liter V-6 are based on the same architecture, but the twin-turbo uses specified components and other features for its turbocharging.

The new V-6 engines have been designed for "higher performance and greater efficiency" and GM says they will set a new benchmark for their class in horsepower and fuel efficiency. The new V-6 twin turbo is estimated to produce 400 horsepower and 400 foot-pounds of torque, which the automaker says makes it one of the most powerful V-6 dual overhead camshaft engines in the world.

GM says the twin turbo is a segment first: A turbo six-cylinder with cylinder deactivation, which temporarily deactivates two cylinders when not needed, and stop-start technologies to save fuel. Stop-start shuts down the engine at stop lights and automatically restarts when a driver takes a foot off the brake. When paired with the 8-speed transmission, Cadillac predicts the engine will boost fuel economy as much as 9 percent.

Cadillac engineers say fuel economy is not a customer priority in the luxury market, but, under pressure from stricter federal fuel economy mandates, manufacturers are replacing V-8 engines with turbo V-6s as a premium engine option. "The government is limiting V-8 penetration," Leone said, "but you will still see them in top of the line products like our V-series."

While the 3.6-liter V-6 gets a new automatic transmission, GM said the twin turbo will be mated to GM's similar, more robust Hydra-Matic 8L90 paddle-shift eight-speed. The company said GM's twin turbo V-6's horsepower is 27 percent higher than the BMW 740L's 3-liter twin-turbo V-6 and 29 percent more than Audi A7's 3-liter supercharged V-6 engine. The normally aspirated V-6 will produce 335 horsepower compared to Infiniti's much-admired, 330-horsepower, 3.7-liter V-6. GM said the engines will set a new benchmark for quietness.

"Cadillac's elevation on the world stage is driven in great part by its advanced powertrain technology and the all-new 3.0-liter twin turbo powers past the traditional segment leaders with higher degrees of the performance and refinement their reputations were built on," Rich Bartlett, GM assistant chief engineer, said in a statement.

The new engines will be built at GM's Romulus Powertrain Operations plant. GM previously announced it would invest $540 million in the Romulus plant for V-6 engines. In 2013, GM said it would lay off 560 hourly and temporary workers at the Romulus plant to retool for a new V-6 engine, which it then said would go into production in late 2015.

Melissa Burden covers GM. Find her at or (313) 222-2319 or follow her on Twitter: MBurden_DN| Henry Payne is auto critic for The Detroit News. Find him at or follow him on Twitter: @HenryEPayne.