We got our first look at the new standard-issue 2013 Mercedes-Benz GL-Class in April at the New York Auto Show. Now, the wraps have come off of its more attitude-intensive sibling: the 2013 Mercedes-Benz GL63 AMG. Like the GL350 BlueTEC turbodiesel, GLK450 and GL550 models that go on sale this fall, it will come standard with M-B's 4Matic all-wheel-drive system. Unlike that less-potent trio, the new GL63 AMG won't be hitting showrooms until the first quarter of next year. As with other AMG-spec offerings, the GL63 AMG matches subtle cosmetic enhancements with not-so-subtle powertrain and suspension upgrades. Key visual changes to the exterior include a restyled front fascia with bolder lines, bigger air intakes and additional black-and-bright accenting in the grille and lower valence. The profile is augmented by meaty 295/40 performance tires on 21-inch AMG machine-polished lightweight alloy wheels residing in the GL63 AMG's tastefully flared fenders complemented by illuminated side sills and AMG stainless steel running boards while the rear quarters benefit from a distinctive AMG rear valence/diffuser that also boasts more black-and-bright elements as well as twin chrome dual exhaust outlets.

The cabin also gets a typical AMG makeover, with the performance division adding its own signature touches to the four-spoke multifunction steering wheel, power adjustable front sport seats, instrument cluster, rubber-studded stainless steel pedals and floor mats punctuated by a host of AMG badges. While the dash and door trim are clad in MB-Tex, the seats are all wrapped in premium leather set off with contrast stitching.

At the heart of the 2013 Mercedes-Benz GL63 AMG is AMG's potent 5.5-liter twin-turbocharged V8, which makes 550 horsepower and 560 lb-ft of torque in this application. Backed by a 7-speed AMG Speedshift automatic transmission, it can send the new GL63 AMG sprinting from 0-60 mph in 4.9 seconds and on to a terminal velocity of 155 mph - both electronically limited. The engine/trans combo also is fitted with M-B's ECO start/stop system. It offers the choice of a Controlled Efficiency mode that includes softer throttle/shift mapping and shuts down the engine when the vehicle comes to a stop as well as more enthusiast-flavored Sport and Manual settings that quicken response and lock out the auto start/stop action.

Beyond its upgraded wheel/tire fitment and a 40/60 basic torque split on the full-time 4Matic system, the 2013 Mercedes-Benz GL63 AMG features a bespoke AMG Ride Control Airmatic adjustable air suspension with self-leveling function plus M-B's Adaptive Damping System, Active Curve Control and an AMG speed-sensitive variable power steering setup. Stopping power is provided by AMG high-performance brakes with fade-foiling ventilated/perforated rotors and bright red calipers.

While excelling in excitement, the new Mercedes-Benz GL63 AMG never loses sight of its luxury pedigree. Other standards of note include bi-xenon headlamps, multi-contour power adjustable front sat s with massage capability, tri-zone climate control, a COMAND telematics package with Bluetooth/USB, power tilt/sliding sunroof, dual rear-seat easy entry, power tailgate and Keyless Go along with Collision Prevention Assist and Crosswind Stabilization. The equally impressive option roster includes a Bang & Olufsen BeoSound AMG Surround Sound premium audio package, Panorama sliding glass roof, a 360-degree camera system, Brake Assist Plus, Active Lane Keeping Assist, Active Blind Spot Assist and Distronic Plus adaptive cruise control including Pre-Safe Brake.

Like the other members of the GL-Class, pricing for the 2013 Mercedes-Benz GL63 AMG will not be released until closer to its on-sale date.