Photo of 2015 CLS-Class courtesy of MBUSA.

Photo of 2015 CLS-Class courtesy of MBUSA.

Mercedes-Benz has extensively redesigned its four-door CLS-Class, adding a new bi-turbo V-6 engine, nine-speed transmission, and exterior redesign.

The 2015 CLS400 gets a new 3.0-liter V-6 bi-turbo engine that produces 329 horsepower and 354 lb.-ft. of torque. The CLS550 continues to offer a 4.6-liter V-8 that produces 402 horsepower and 443 lb.-ft. of torque.

The models also get a new nine-speed automatic transmission with a hydrodynamic torque converter that replaces a seven-speed transmission. The rear-wheel-drive CLS550 will be the first model to get the new transmission.

Mercedes-Benz has also upgrades the interior with a new SD Card-based Garmin Map Pilot navigation system.

The lineup now gets LED headlights as a standard feature with Multibeam LED headlights as an available option.