Just a few weeks after revealing the CT6 sedan in New York, Cadillac made a major announcement about the all-new sedan in Shanghai: There's a plug-in hybrid variant coming that Caddy claims will get "more than double the fuel economy of the conventional powertrain offerings."
The plug-in drivetrain will pair , GM's 2.0-liter turbo inline-four, with a new Electric Variable Transmission containing two electric motors to send up to 335 horses and 432 lb-ft of torque to the rear wheels only. An 18.4 kWh battery pack nestled behind the rear seats powers the electric motors.
Cadillac says the plug-in CT6 will offer three driving modes: Normal; Sport, which stiffens steering and sharpens throttle response; and Hold, which propels the car strictly with gasoline to preserve battery charge. Like the Cadillac ELR, the hybrid CT6 will have steering wheel-mounted paddles to activate on-demand electricity regeneration, calling up deceleration similar to a manual downshift in a conventional car.
What's that add up to, economy-wise? Cadillac makes a big promise in touting a more than twofold increase in fuel economy, but right now that's a hazy claim: Fuel economy estimates aren't yet available for the conventional CT6, and the eventual rating for the plug-in variant will be in MPGe, a testing method which takes maximum advantage of electric-only driving range before switching over to petrol power. Cadillac promises full numbers closer to the CT6's market debut.
Given GM's incredible focus on keeping the CT6 lightweight—Cadillac claims despite the CT6 being the marque's current range-topping sedan in size—it's not impossible to imagine a plug-in hybrid variant getting stellar mileage in ideal conditions. Generally speaking, though, we're more interested in the twin-turbo V8-powered CT6 that Cadillac president Johan de Nysschen keeps telling us will happen.