Introduction

The Mercedes-Benz GL-Class seats up to seven in luxury and offers a choice between a frugal diesel or an enthusiastic gasoline engine. Manufactured in America, the three-row luxury wagon targets the U.S. market and has proven to be quite popular in the luxury SUV league. The GL-Class is intended more for all-weather traction than off-road capability. 

Introduced for 2007, it was redesigned for the 2013 model year. There are no significant changes for 2016. 

Four GL-Class trim levels are offered, each with a distinct powertrain. All have a 7-speed automatic transmission and 4MATIC four-wheel drive. 

Rugged good looks combine with flexible, abundant interior space. The GL-Class offers fine road manners. Air shock absorbers in a fully independent suspension ensure a gentle, almost pillow-soft ride. In some versions, an adaptive suspension is especially adept at minimizing body lean. Feedback could be better from the electric power steering, but it's not excessively light in feel. 

An option package adds a low range and locking center differential, while ride height can be adjusted between 8.5 and 12 inches. A properly equipped model is rated to tow up to 7,500 pounds. 

The least expensive and most frugal of the GL-Class is the smooth-running GL350 BlueTec. Its six-cylinder turbodiesel engine produces 240 horsepower, but a whopping 455 pound-feet of useful torque. 

Not much higher-priced, the GL450 uses a 3.0-liter twin-turbo V6 that develops 362 horsepower and 369 pound-feet. The GL550 features a twin-turbocharged, direct-injected 4.7-liter V8 rated at 429 horsepower. Topping the list, the GL63 AMG unleashes 550 horsepower from its twin-turbo 5.5-liter V8, promising 0-60 mph acceleration below five seconds. 

The Mbrace2 connectivity suite links smartphones to the COMAND infotainment system and permits certain remote-control functions. Bluetooth and HD radio are also standard. So are a power tailgate, power third-row seats, and a sunroof. 

On the safety front, the GL-Class offers lane-keeping assist, Collision Prevention Assist, blind-spot monitoring, and adaptive cruise control. 

Lineup

GL350 BlueTec ($64,550) comes with MB-Tex (vinyl) upholstery, automatic climate control, heated power front seats, power third-row seats, a DVD changer with HD radio, COMAND interface, sunroof, and power tailgate. GL450 ($66,200) is configured similarly to the GL350 BlueTec, but with a gasoline V6 engine. 

GL550 ($91,300) has a 4.7-liter V8 and a selection of active-safety features, as well as an 830-watt Harman Kardon Logic 7 audio system. 

GL63 AMG ($121,100) has the high-performance 5.5-liter V8 and nearly every feature that's optional on lower trims. 

Safety features include front knee airbags and full-length curtain airbags, plus a rearview camera and Attention Assist. Collision Prevention Assist uses cameras to sense impending collisions and applies brakes to mitigate impacts or to stop fully, from below 20 mph. 

Walkaround

Both rugged-looking and contemporary, the GL-Class continues to emphasize traditional SUV design, shunning the chrome and glitter that identify some luxury utility vehicles. Bodywork melds just enough soft curves, extended creases, and incisive angles into an SUV design that could hardly be any cleaner. 

The familiar Mercedes-Benz grille is especially pronounced on the GL-Class. A long silhouette enhances the wedge shape that stems from bodyside character lines. Overall, the GL-Class is more subdued in appearance than many competitive full-size SUVs. Front and rear ends have LED lighting. The GL550 adds flared wheel arches and 21-inch wheels, while the GL63 AMG gets its own look. 

Interior

Within the rugged GL body is an immense, comfortable cabin, nearly as versatile as a minivan's. High-quality materials appear throughout, including an upholstered dashboard and soft-touch surfaces. 

Leather upholstery and wood trim impart a warm, rich glow. Upper-trim interiors feature olive ash wood and perforated leather. 

Front passengers in upper models can ride on ventilated seats with a massage function. Second-row seats may be heated. Power-folding third-row seats stow to add cargo space, while optional power assistance can tuck away the second-row seats. Even adults will fit into the third row, which is split 50/50. 

Cargo volume can expand from modest to practically cavernous. With the third row up, cargo space totals 16 cubic feet. Flip them forward, and you have 49.4 cubic feet. With the second row folded forward, space grows to 93.8 cubic feet. 

Passengers don't have to step high to get aboard. Second-row seats benefit from wide door openings. An Easy-Entry feature improves access to the third row. A power control can slide front seats forward, but its motor is noisier than expected. 

A console knob operates the COMAND infotainment system, which has a 7-inch screen but isn't as easy or intuitive as those in rival SUVs. 

Driving Impression

From behind the wheel, a GL-Class doesn't really feel like an SUV. That's because it's one of the most composed full-size models out there, helped by electric power steering and, if installed, optional active anti-roll bars. That option is costly, but can make a difference when the GL starts to lean into corners. Larger tires can jiggle the ride somewhat. 

Though lacking in feedback, steering feel, at least on models with smaller wheels, doesn't feel especially light. The variable-ratio setup responds differently at low speeds, though the transition isn't as evident as in Mercedes-Benz passenger cars. 

Air springs are tuned for a cushioning ride, and the GL-Class is isolated from road vibration. Optional active dampers have Sport and Comfort modes, which can slightly soften the highway ride or tighten it up as needed. Either way, lateral pitching of passenger heads is limited. 

Some turbo lag can occur in a BlueTec, because of the nature of the smooth, strong diesel engine, but fuel economy is EPA-rated at 18/26 mpg City/Highway, or 21 mpg Combined. That's one reason the BlueTec is one of our favorites. The 4.7-liter V8 can be a tad coarser than the silken Mercedes-Benz V8s in some models. 

Gasoline models, especially V8s, are thirsty. The twin-turbo V6 is EPA-rated at 17/21 mpg City/Highway, while the GL550's bigger V8 is estimated at 13/18 mpg. Despite its additional power, the GL63 AMG isn't much worse, EPA-rated at 13/15 mpg City/Highway. 

Summary

The Mercedes-Benz GL-Class rides smoothly and is luxuriously equipped, but it is expensive. We'd pick the GL350 BlueTec, based upon its combination of diesel torque and fuel efficiency, as well as the excellent road behavior delivered by each version. 

Driving impressions by Kirk Bell. James M. Flammang contributed to this report.