2014 Mercedes-Benz ML63 AMG

The ML63 AMG is the potent, sport-focused model of Mercedes-BenzïÃ'¿Ã'½s M-Class mid-size luxury SUV range. Though the wisdom of a high-performance variant of a big, heavy and aerodynamically challenged SUV is debatable, customer demand is strong, and Mercedes has responded with the most powerful ML63 AMG to-date.

Visually differentiating the ML63 AMG from its less fire-breathing siblings are aggressive front and rear fascias along with new side skirts running the length of the vehicle to connect the more sporty design. The front end flows into distinctive front fenders, which are 0.4 inches wider on each side than the standard ML in order to accommodate larger AMG alloy wheels.

Unique "V8 BITURBO" badging hints at what lurks under the hood and also clarifies the switch from the outgoing model's 6.2-liter engine. Out back, the lower fascia is centered around a unique black diffuser that houses the AMG sports exhaust system with two sets of chrome twin tailpipes.

Inside, the cushy five-passenger cabin is dressed up with special touches like a special four-spoke steering wheel, aluminum trim elements and AMG badges incorporated into the backrests of the seats, which are specially bolstered sport units with designo premium leather and contrasting double topstitching.

Power to the People
At the heart of this family-friendly performance vehicle is AMG's latest monster motor, a twin-turbo 5.5-liter V8 that produces a prodigious 518 horsepower and 516 lb-ft of torque while still managing 33 percent better overall fuel economy than the outgoing motor. If that isn't enough thrust to take the kids to soccer practice, an optional AMG Performance Package cranks up the boost from 14.0 to 18.8 psi, resulting in 550 ponies and 560 lb-ft of twist.

Shifting duties are handled by the AMG Speedshift Plus seven-speed automatic transmission, which brings to the table no less than three unique driving programs.

The first driving program can be accessed by setting the vehicle to the "Controlled Efficiency" mode, aka eco-mode, which sets the engine's start-stop to active, delivers more comfort-oriented shifts and makes earlier gear changes to stay in the "green spot," which is not to be confused with the sweet spot in the power band that maximizes power. This mode is so aggressively non-aggressive, in fact, the ML63 will typically launch in second-gear while in Controlled Efficiency mode, bypassing the gas-hungry first gear altogether.

Next up are Sport and Manual modes, both of which fully disable the start-stop engine function, and instead put the engine in a "let's do this" mindset. Where Sport Mode will shorten shift points and still work as a normal automatic transmission, Manual Mode will leave gear change duties in the hand of driver input.

Also, both modes make use of retarded ignition and ignition during upshift at full throttle in order to produce quicker shifts.

Power is put the ground via Mercedes' 4Matic all-wheel-drive system, which distributes engine power at a ratio of 40:60 to the front and rear axles and pays dividends on the drag strip as well as slushy roads.

There's a penalty at the pump for all that power and performance: the ML63 is rated at 14 mpg in the city and 18 mpg on the highway.

Corner Carver
Ensuring that ML63 AMG isn't just a straight-line special are handling-enhancing features like an AMG-developed sports suspension with AIRMATIC air springs, independent damper struts, automatic level control and Adaptive Damping System (ADS), which are all combined for the first time with Active Curve System, which provides active roll stabilization.

When it comes time to bring the party to a halt, the ML63 AMG is equipped with a high-performance braking system with high fade resistance, featuring ventilated and perforated brake discs at all four corners. Front discs come in at 15.4 inches, while the rear measure 13.6 inches.

The brakes of course are only part of the stopping equation as the wheels and tires cannot be forgotten. The ML63 AMG features five-spoke, 20-inch alloy wheels which are coated in a titanium grey high-gloss finished, wrapped in 265/45/R20 tires on all four corners.

Standard and Optional Features
The ML63 AMG comes lavishly equipped with a navigation system a seven-inch display and rear-time traffic and weather updates, a Harmon/Kardon Logic 7 surround sound system with Bluetooth audio streaming, HD radio and a USB port, a sunroof, PARKTRONIC with Active Parking Assist and heated and active ventilated front seats with 10-way power adjustability.

Aside from the aforementioned engine mods, the available Performance Package adds an AMG Performance steering wheel with DINAMICA grips, red brake calipers and a carbon fiber engine cover.

Occupant Safety
Mercedes-Benz has long been known for its safety features, and the ML63 AMG will certainly not tarnish that reputation. In addition to ABS and ESP stability control, the SUV 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.

High-tech safety items include Blind Spot Assist, Lane Keeping Assist and Pre-Safe, a system that charges the brakes when it detects an impending impact in order to limit the severity of the wreck as much as possible.

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.

New for the latest model year is Mercedes' Collision Prevention Assist, a radar-based system that works to prevent or mitigate collisions. Between 20 and 155 mph, the system monitors the distance between the M and the vehicle in front of it, emitting visual and acoustic warnings and priming the brakes if it senses that a collision is imminent.

Key Competitors
The ML63 AMG has a range of worthy rivals including the precise-handling BMW X5 M, the stupid-fast Porsche Cayenne Turbo and the off-road capable Range Rover Sport Supercharged. The less-expensive Jeep Grand Cherokee SRT8 is also a capable performer that, interestingly enough, shares a basic platform with the ML63 AMG.