2015 Mercedes-Benz CLS63 AMG 4MATIC

Mercedes-Benz pioneered the notion of a premium four-door coupe with the first CLS in 2004. Despite the somewhat counter-intuitive nature of a sedan masquerading as a coupe, the CLS was a success, with customers lining up in droves and competitors from Audi to Hyundai stealing styling cues. The CLS63 AMG is the range-topper of the second-generation CLS, a car that mixes performance, style and luxury in equal measure.

Recent Changes
For the latest model year, the CLS gains a moderately updated front fascia that falls in line with Mercedes' latest design language. Inside, the most noteworthy modification is the addition of a display screen that pops out from the top of the dashboard, a setup that allows engineers to update the screen without having to fully redesign the center stack.

Essentially a re-bodied E63 AMG 4MATIC, the CLS63 AMG 4MATIC puts looks above all with a lowered roof, puckered tail and curvy dashboard. While the E-Class is practical and formal, the CLS seeks to be evocative and emotional.

Under the hood rests the heart of the CLS63 AMG: a hand-made twin-turbocharged 5.5-liter V8. This twin-turbocharged and direct-injected monster was recently massaged to increase power from 518 horsepower and 516 lb-ft of torque to 550 ponies and 531 lb-ft of twist. Should potential customers feel that those numbers are inadequate, a more potent S-Model version of the car cranks up the boost from 13.0 to 14.5 psi to make 577 ponies and 590 lb-ft.

The benchmark zero-to-60 mph sprints takes just 3.6 seconds for the standard CLS63 AMG 4MATIC, while the S-Model can do the deed in 3.5 seconds en route to an electronically-limited top speed of 186 mph. Both models are rated at 16 mpg in the city and 24 mpg on the highway.

All CLS63 AMG 4MATICs utilize a seven-speed "MCT" automatic transmission that ditches a conventional torque converter for a wet clutch pack that makes shifts quick and smooth, even at low speeds (something that cannot be said of competitors' dual clutch automatics). It features rev-matched downshifts and an "eco mode" that engages the stop/start system, which switches off the engine at idle to save fuel.

The gearbox sends power to all four wheels via a performance-tuned version of Mercedes' 4MATIC all-wheel-drive system. The benefits of 4MATIC compared to the old rear-drive setup are numerous - it puts the sedan's massive power to the pavement more effectively, is four-season-friendly and, with a 33/67 front/rear output split under normal driving conditions, maintains enjoyable rear-drive-like dynamics.

A limited-slip rear diff - optional on the normal sedan and standard on the S-Model - further optimizes traction, while the stability control system of all CLS63 AMG 4MATICs can be set to provide rear brake-based torque vectoring to minimize understeer.

Helping to keep things under control when the road gets curvy is the AMG RIDE CONTROL sports suspension that features a specially designed front axle with a 1.9-inch increase in track width relative to the normal E-Class, in addition to independent wheel carriers for increased negative camber at the front to improve grip during performance driving.

Further features include steel suspension struts on the front axle and air suspension struts on the rear axle with an automatic level control system and an electronically controlled damping system, which automatically adjusts the damping characteristics depending on driving conditions and reduces body roll. The driver can switch between the three suspension modes of "Comfort," "Sport" and "Sport plus" at the touch of a button.

Should a red light or stop sign impede the driver's backroads fun, the CLS63 AMG 4MATIC is prepared for the occasion with six-piston front and four-piston rear brakes with 14.2-inch cross-drilled rotors all around. Carbon ceramic brakes with massive 15.8-inch rotors for maximum stopping power are optional.

One of the few weak spots on the car, at least for enthusiasts, is the steering. It's a power-assisted, electrohydraulic setup that offers a dearth of information concerning the activities of the front wheels, though it is accurate and isolated enough for miles of easy freeway cruising.

The Inside Story
Inside, the opulent interior of the standard CLS-Class is upgraded with extras like a three-spoke leather/alcantara steering wheel with a flattened rim at both the top and bottom to allow improved driver control. Other AMG-specific touches include sports seats and a new IWC-designed analog clock.

Mercedes' COMAND infotainment system remains; controlled either by voice commands, a central knob or steering wheel-mounted buttons, it integrates the sedan's audio, navigation and Bluetooth-based connectivity functions into a single unit - a seven-inch display screen mounted on the dashboard.

An optional mbrace system adds a host of cloud-based goodies, including a concierge service, location-based traffic and weather updates, stolen vehicle location assistance, automatic collision notification and more. Available apps add internet browsing, Google local search with street view, Yelp reviews, Facebook access and news reports. Owners can even use an mbrance smartphone app to remotely lock, unlock or locate their sedan.

Standard and Optional Features
The standard features list is extensive, including navigation, a 14-speaker Harmon/Kardon LOGIC7 5.1-channel AM/FM/CD/HD radio surround sound system, a power moonroof, 14-way heated front seats, dual-zone climate control and 19-inch alloy wheels.

For those seeking even more luxury, a number of options packages can be spec'd to make for a truly decadent automobile.

The Premium 1 Package brings active ventilated and active multicontour front seats, a proximity key, a rearview camera and an electronic trunk closer.

The Driver Assistance Package nets Active Blind-Spot Assist, Active Lane Keeping Assist and Distronic Plus (an active cruise control system) with Pre-Safe Brake (detailed below).

Stand alone-options include carbon ceramic brakes, a Bang & Olufsen sound system, PARKTRONIC active parking assistance system, Night View Assist PLUS with Pedestrian Detection and a carbon-fiber spoiler.

Occupant Safety
Mercedes-Benz has long been known for its safety features, and the CLS63 AMG 4MATIC will only add to that reputation. In addition to ABS and ESP stability control, the car boasts nine supplemental restraints including two-stage front air bags, a knee air bag for the driver and pelvic air bags which work together with curtain and side air bags to provide extra protection for front occupants in dangerous side-impact collisions.

Also standard is an ATTENTION ASSIST system that can alert the driver to the first signs of drowsiness, a factor that causes more than 100,000 accidents a year in the U.S.A steering sensor is coupled to smart software that uses 70 parameters to establish a unique driver profile during the first 20 minutes of driving. Between 50 and 112 mph, the system identifies the erratic steering corrections drivers make as they begin to get drowsy and triggers an audible warning and a "Time for a Rest?" message with a coffee cup icon in the instrument cluster.

The optional Pre-Safe Brake system detects impending collisions with vehicles or pedestrians and can automatically apply braking force to avoid or mitigate the severity of the crash

Key competitors
Looking for a high-performance four-door-coupe? Besides the CLS63 AMG, there are plenty of excellent choices, including the BMW M6 Gran Coupe, the Audi RS7 and the Porsche Panamera Turbo S.