As large as the GL may appear, it's 2 inches shorter than the R-Class touring wagon, which also has three rows of seating, though with room for only six occupants.

The GL is built using unibody construction rather than the body-on-frame design that full-size pickups and SUVs traditionally use. Mercedes notes that because of this architecture, the GL-Class weighs in at anywhere from 300 pounds to 600 pounds lighter than its full-size competitors. To make sure the GL class is strong enough, 60 percent of the vehicle structure is made from special high-strength steel.

Interior Features

While the GL may look sleeker than its competitors, Mercedes brags that the 2007 GL 450 offers both best-in-class interior room as well as ease of entry and exit.

With all seats in their upright position, there's still 14 cubic feet of storage between the third-row seatbacks and the closed rear hatch door. A power folding feature for the third row is standard equipment on the GL with controls near the rear hatch and next to the right-side second-row passenger's seat. Power down those third-row seats, and cargo capacity expands to 43.8 cubic feet. Fold down the 60/40-split second row seats and the GL provides as much as 83.3 cubic feet for cargo. There's also room under the cargo floor for a full-size spare tire.

Standard equipment includes eight-way power front seats, 14 air conditioning outlet vents, eight cup holders, air vents, and reading lamps.

The interior layout is familiar to Mercedes drivers, with either faux or real leather trim for the seats (Mercedes notes that not all luxury car buyers want real leather seating surfaces), wood trim and metal rings around gauges, air vents, and cup holders.

The second-row seats provide ample legroom. When occupied by only two people, the back of the center section can be folded down as an armrest and storage tray.

We climbed into the third row and found room for two adults to ride back there, each in a separate seat. The room is enhanced by foot wells for your feet so you don't sit with your knees at chest level, and even the third-row seats are thickly padded to provide comfort. Fears of claustrophobia back there evaporate quickly thanks to the standard sunroof that extends over the third row.

The GL can be equipped with a 440-watt, 11-speaker harmon/kardon Logic 7 sound system, with Sirius Satellite Radio and with a DVD video entertainment system with screens mounted in the rear of both front-seat headrests and with a 6CD changer.

Driving Impressions

Driving the 2007 Mercedes-Benz GL 450 doesn't feel at all like driving the typical full-size sport utility vehicle. While this is a substantially sized vehicle, it is not truck-like. The Mercedes has a much more car-like dynamic.

The 335-hp V8 engine can propel the GL 450 from a standing start to 60 miles per hour in a car-like 7.4 seconds. This powerplant, with four valves per cylinder, is part of a brand new family of V8 engines from Mercedes-Benz.

A standard, seven-speed automatic transmission helps keep the engine operating in the sweet part of a power band that provides maximum torque from 2700 rpm all the way up to 5000. Mercedes notes that the GL is the only full-size SUV offering such a seven-speed gearbox.

The 4MATIC four-wheel-drive system features front, center and rear differentials. The sure-footed 4MATIC system is designed to maintain mobility even when only wheel has traction. In normal driving, the system distributes power equally to front and rear wheels. The system includes DSR, a sort of cruise control for regulating downhill speed, and Hill-Start Assist, which keeps the GL from rolling backward when launched after being stopped on uphill slope. 4MATIC also adjusts anti-lock brake controls to provide quicker stops on slippery and unpaved surfaces when off-roading.

Airmatic is an air suspension system that uses air bladders instead of coil springs to adjust ride height by as much as three inches as well as ride firmness and body control parameters, so the driver can select from comfort and more aggressively sporty settings. The system automatically lowers the vehicle to enhance handling and aerodynamic efficiency at speeds of 77 mph or higher.

Those serious about venturing far from pavement can opt for a special off-road package that includes special wheels and tires, a two-speed transfer case, locking center and rear differentials, adaptive dampening and with ground clearance height-adjustment options of as much as 12.4 inches, compared to the standard 7.9 inches of clearance.

We did our driving on freeways in and out of San Francisco's airport and on roads through Napa Valley wine country. Steering feedback was consistent, brakes (14-inches in diameter on the front wheels and 13 inches on the rear) were responsive and consistently predictable and the GL 450 offered nice balanced dynamic capabilities when hustled through the curves on the narrow, hilly roads that wind through the vine-covered hillsides.