Although Cadillac’s flagship CT6 sedan has been on the market for about a year, the newest and greenest member of the family is just now arriving in showrooms in the form of the 2017 CT6 Plug-In Hybrid. It’s fair to say we’ve been pretty impressed overall with the conventional version of Cadillac’s flagship 4-door and were looking forward to spending some time behind the wheel of its gas/electric counterpart. Despite what was a surprisingly brief encounter in the Los Angeles area, our experience did confirm this most fuel-efficient and environmentally friendly variation on the CT6 possesses some notable merits of its own.

Unveiled in U.S. spec last fall at the Los Angeles Auto Show, the CT6 Plug-In matches the same sophisticated 2.0-liter turbocharged 4-cylinder engine used in the base CT6 with a new electric variable transmission (EVT) that contains two motors–one induction, one permanent magnet–along with three planetary gear sets and five clutches. The first use of this “Blended PHEV” configuration in any GM product automatically helps smooth operation whether you’re running the CT6 Plug-In on battery power alone or with engine assist when the charge is depleted or you step heavily into the throttle. Collectively, the Plug-In drivetrain develops 335 horsepower–the same as the CT6’s naturally aspirated 3.6-liter V6–but 432 lb-ft of torque, which is 32 lb-ft more than the range-topping 3.0-liter Twin-Turbo V6. All of that motive force heads to the rear wheels and allows the car to sprint from 0-60 mph in a claimed 5.2 seconds, which makes it nearly as quick off the line as the AWD Twin-Turbo.

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When cruising takes precedence over stoplight-to-stoplight shootouts, the CT6 Plug-In offers a respectable 31-mile pure electric range. Credit that stat to  a 18.4-kWh liquid-cooled battery pack that also lets it run up to 78 mph in EV-only mode while contributing to a 440-mile overall range and 62 MPGe combined EPA rating. Using identical lithium-ion chemistry found in the latest Chevy Volt, the Plug-In’s aft-mounted battery does trim trunk space from 15.3 to 10.6 cu ft. Cadillac duly notes there’s still enough room to swallow a pair of regulation-size golf bags. Recharging takes about 4.5 hours on a dedicated 240V/20A system, but those with double the patience and them some also can use the supplied cable to replenish the battery on a standard 120V outlet.

Regen braking on demand

The new Plug-In uses the same aluminum-intensive Omega platform as the other CT6 models and despite carrying roughly 700 pounds of additional curb weight,  we found it maintains a good deal of their baseline agility. Like most of its contemporaries, this new Cadillac Plug-In offers several driver-selectable operating modes. “Normal” balances performance with economy; “Sport” quickens throttle response and ups steering effort; and “Hold” saves battery charge by increasing the degree to which the engine provides the primary motive thrust.

The highly efficient regenerative braking system on the CT6 Plug-In does boast one notable touch in the form of its trick multi-level Regen on Demand setup. Unlike single-mode systems in Chevy’s Volt and Bolt, the Cadillac offers four increasingly intense choices of braking accessible via steering-wheel mounted up/down paddles. However, the most pronounced, which delivers 0.18g of deceleration, is only programmed to bring the car down to a 1-mph pace, so true one-pedal driving is not in this Caddy’s cards. That caveat aside, adapting to the system proved a fairly quick, easy process and effectively bolsters the conventional brakes, which we felt lacked the same degree of confident linearity displayed in the regular CT6.

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Cabin dimensions are identical to a conventional CT6 in both front and rear seating areas, although the CT6 Plug-in does get a number of detail enhancements. Heading the list are dedicated display screens in its main instrument cluster and CUE center stack that keep tabs on a host of EV/Hybrid-related operating data. Available in only one comprehensively equipped trim priced at $76,090 before the $7,500 federal tax credit and any other state or local incentives, the CT6 Plug-In boasts all of the standard features found on a CT6 Premium Luxury model. This includes full LED lighting, a Bose premium audio system with navigation, rear-seat infotainment package, UltraView panoramic sunroof, Comfort Package and the Enhanced Vision Package plus the Driver Awareness and Convenience Package with its full suite of safety/driver assists including head-up display and Night Vision.

While a fair step up from the $54,790 sticker of a base CT6 2.0, Cadillac does point out the new Plug-In stickers thousands below similarly equipped alternative buys like the BMW 740e xDrive iPerformance, Mercedes-Benz S550e and Porsche Panamera 4 E-Hybrid. Admitting the car’s prime appeal will be in China (where it’s manufactured) the automaker believes the CT6 Plug-In also will be a viable player in key hybrid-friendly U.S. markets–most notably, California. Given its laudable combination of performance, economy and luxury, we suspect those with green leanings may well agree.

More Hybrids and Plug-In Vehicles:

2017 Honda Accord Hybrid First Review

2017 Kia Optima Hybrid and Plug-in Hybrid revealed

2017 Toyota Prius Prime Quick Take


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