Here are the things you need to know about the CT6: It's a rear-wheel, or all-wheel-drive, car meant to take on BMW, Mercedes, and Audi at the top of those carmakers' pantheons. As such, based on our experience with the CTS and ATS, it's likely to be pretty exceptional out of the gate when it debuts this coming year. To keep the chassis light, Cadillac uses aluminum for 64 percent of the body, including all of the car's exterior, shaving 200 pounds, and resulting in a much stiffer structure even while reducing weight. In top engine guise, it gets a new twin-turbo, 3.0-liter V-6, with output estimated at 400hp, 400 lbs-ft of torque. This motor also gets both cylinder deactivation (the V-6 reverts to four-cylinders during cruising), and start-stop functionality during stop-and-go traffic. All-wheel drive is standard on all CT6 six-cylinder models, with rear-wheel drive on the base, 2.0-liter, 265hp four-cylinder edition. By the way, Cadillac says the car, despite its substantial size, will weigh as little as 3,700 pounds, which is about the weight of the current CTS, despite being a good half-foot longer.