The Cadillac CT6 is one of the most anticipated debuts of the 2015 New York Auto Show, and Cadillac has just honed the edge of our interest: it will pack a 3.0-liter twin-turbocharged V-6 engine good for 400 horsepower and 400 pound-feet of torque.
That’s the top-line engine offering in the CT6, and it will also feature one other new aspect: cylinder deactivation. Turning off one cylinder per bank, the technology allows the engine to function as a V-4 under light loads. The CT6 engine will also feature stop-start technology. Cadillac claims this is the only twin-turbo V-6 engine in the world with both cylinder deactivation and stop-start.
Sitting behind the new twin-turbo V-6 will be GM’s brilliant Hydra-Matic 9L90 eight-speed automatic transmission, versions of which are also found in the Chevy Corvette and GM’s pickup and SUV lines.
3.0-liter twin-turbo V-6 for the 2016 Cadillac CT6
Peak torque in the new CT6 engine will arrive at just 2,500 rpm, holding there until 5,000 rpm, giving the car a strong mid-range torque plateau that should translate to easy pulling power in any gear, as well as an unflustered quality.
The new turbo V-6 also features some interesting turbocharger technology and design aspects, including low-inertia turbos with titanium-aluminide turbines, which translates to quicker turbo spool-up. A 9.8:1 compression ratio, forged crankshaft, reinforced pistons, hardened exhaust valve seat material, and sodium-filled exhaust valves also contribute to the engine’s performance potential—and may allow a fair amount of headroom for the aftermarket.
New Cadillac 3.6-liter V-6
Cadillac is also announcing an all-new 3.6-liter V-6 to replace the current engine used in the ATS and CTS lines. The new 3.6-liter promises to be quieter and smoother, as well as offering cylinder deactivation and stop-start function. Output is stated at 335 horsepower and 284 pound-feet of torque, which Cadillac claims is the highest of any normally aspirated V-6 using regular fuel. Upgrades to the new engine over the previous version include: a stiffer aluminum block, a forged steel crankshaft, polymer-coated reduced-friction pistons, improved cooling, higher-flow cylinder head design, and a new variable displacement oil pump for improved efficiency.
The new 3.6-liter V-6 will be paired with an all-new Hydra-Matic 8L45 eight-speed automatic transmission.
Both the new normally aspirated V-6 and 8L45 transmission will make their debuts in the CT6 before filtering into the ATS and CTS ranges.
GM Hydra-Matic 8L45 eight-speed automatic transmission
There's been no word yet on the plug-in hybrid powertrain suggested last year for the CT6 by GM product development chief Mark Reuss, but all should be revealed in just a few weeks at the 2015 New York Auto Show.