American luxury sedans were once dismissed, often rightly, as lumbering land yachts. But Cadillac has honed its reputation with assassins like the 477-kilowatt (640-horsepower) CTS-V, and now it has applied the same thinking to its flagship sedan. Yes, the CT6 has a street presence that stretches to nearly 5.2 meters (17 feet), which is longer than many SUVs. But remarkably, this Caddy is lighter than a Mercedes S550 by some 450 kilograms (1,000 pounds).
The advanced Omega chassis uses 11 different materials to lose those pounds, including aluminum castings that, viewed in a cutaway model, look like computer-modeled works of art. The 13 castings dramatically reduce the number of connection points in the ultrarigid chassis, each a potential stress point: Instead of 35 stamped parts in the structure, now there are only two. Throw in aluminum body panels and nearly two-thirds of the Caddy, by weight, is formed from the lightweight metal.
The Cadillac feels so sprightly that it gets along fine with a thrifty four-cylinder engine, in turn the lightest CTS at 1,659 kg (3,657 lb). The pace quickens with an optional 301-kW (404-hp) twin-turbocharged V-6. The lusty V-6 saves fuel by deactivating unneeded cylinders and by stopping and starting the engine at every pause. It also conserves energy with the turbocharger’s featherweight titanium-aluminide turbine wheels.
Cadillac pioneered the magnetic suspension now used by such carmakers as Ferrari and Audi, and the latest version of its Magnetic Ride Control reacts and adjusts to bumps and cornering forces in the blink of an eye. Strike that: Ten times as fast as the blink of an eye, Cadillac says.
Lawrence Ulrich is an award-winning auto writer and former chief auto critic at The New York Times and The Detroit Free Press.