Buyers can choose one of two high-power gasoline-burning engines. An AMG-tuned model is also available.
Billed by Mercedes as the S-Class of crossovers, the GLS is indeed quite similar to a larger, tougher version of the company's oft-lauded flagship sedan. Inside, silver chrome controls, generous amounts of wood trim and soft leather upholstery with contrasting stitching help create an air of high luxury worthy of the S-Class.
Niceties such as heated front seats, a power tailgate, and a sunroof are fitted as standard, as is a cloud-based mbrace system that furnishes access to 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 mbrace smartphone app to remotely lock, unlock or locate their GLS.
There's space for seven adults across three rows of seats, with even the rearmost row being a snap to access thanks to power easy-entry second-row seats. Cargo space measures 16 cubic feet behind the third-row seats; fold down the third row, and 49.4 cubic feet are available, while also stowing the second row unlocks 93.8 cubes.
Powertrains and Handling
Mercedes no longer offers a diesel engine in the GLS, so the lineup is broken down into two models named GLS450 and GLS550, respectively.
The GLS450 uses a twin-turbocharged 3.0-liter V6 that makes 362 horsepower and 369 pound-feet of torque. Next up is the GLS550, whose 5.5-liter V8 provides 449 horsepower and 516 pound-feet of torque.
Both engines shift through a nine-speed automatic transmission. Mercedes' 4Matic all-wheel drive system comes standard, and a low-range gearbox is offered at an extra cost. The GLS can tow 7,500 pounds when it's properly equipped.
As you'd expect, fuel economy is not one of its strong points. The 450 returns 17 mpg in the city and 22 mpg on the highway, while the 550's figures check in at 14 and 19, respectively.
The GLS rides on an AIRMATIC air suspension that automatically adjusts to suit road conditions and can be had with an optional Active Curve System, which works to compensate for body roll during cornering. An optional On- and Off-Road package gives AIRMATIC the ability to raise the GLS and provide 12 inches of ground clearance a 23.6 inches wading capability. The package also includes a two-stage transfer case with reduction gearing, a skidplate and a longitudinal differential lock; the three buyers looking to take their GLS off-road will surely be thrilled.
Standard and Optional Features
The GLS450 comes with leatherette upholstery, genuine Eucalyptus wood trim, heated and eight-way power-adjustable front seats, a sunroof, dual-zone automatic climate control, Bluetooth, a rear-view camera and an AM/FM/CD stereo with HD radio and a six-disc CD/DVD changer. Additionally, both the lift gate and folding third row seats are power-operated for extra convenience. On the outside, the wheels are 19-inch alloys.
The range-topping GL550 gets even more goodies, including 10-way heated and ventilated seats, three-zone automatic climate control and rear air-conditioning, and a Harman Kardon Logic7, Dolby 5.1-certified surround sound system. The Parktronic system with Active Parking Assist is standard as well, as is Burl Walnut wood trim. The standard wheels are 21-inch AMG alloys with a twin five-spoke design.
A long list of options is available, with highlights including a Bang & Olufsen sound system, 20-inch wheels and a surround-view parking system that uses front and rear cameras to create a bird's eye view of the vehicle and its surroundings. There is also a plethora of special order items that include special various leather and color combinations as well as aluminum trim.
Every GLS comes standard with dual front, front side, rear side and full-length side curtain airbags in addition to a driver's knee airbag and traction and stability control systems. Crosswind Stabilization uses targeted braking in the event of strong crosswinds to keep the vehicle on its intended course.
Also standard is a radar-based Collision Prevention Assist system that works to prevent or mitigate collisions. Between 20 and 155 mph, the system monitors the distance between the GLS and the vehicle in front of it, emitting visual and acoustic warnings and priming the brakes if it senses that a collision is imminent. Working in conjunction with Collision Prevention Assist is Pre-Safe, which automatically tightens the seat belts and closes the sunroof if a crash is detected.
Optional safety gear includes Active Lane Keeping Assist, a technology that warns the driver if it detects that the GLS is drifting into an adjacent lane and can apply steering inputs to remain on the proper course. Also available is Active Blind Spot Assist, which uses radar to detect if a vehicle is in the blind-spot area. It provides driver alerts and can also steer the car out of harm's way if the driver accidentally starts to merge into a vehicle.