Unique to the GL550 is a deeper, more aggressive front-end treatment, including a larger three-pointed star. It also features larger fender flares to cover the massive tires and dual-split exhaust outlets.

Seen in profile, the nicely raked windshield and bulging wheel arches over large wheels (18-inch and larger) help balance what is basically a tall and long vehicle. But even being tall and long, the GL doesn't look as bulky as, say, the Chevy Tahoe and GMC Yukon. And even with the squared-off rear edge of its D-pillar, the GL doesn't look as boxy as the Jeep Commander.

Viewed from the rear, the GL offers a formidable stance. It's tall and wide, with a large rear hatch opening and large tail lights, all sitting above a substantial skid plate bracketed on either side by large, rectangular exhaust pipes.

Compared to the ML, the GL is over a foot longer overall and an inch wider in track (the left-to-right distance between the centers of the tires), though it is barely a hair wider overall and not quite an inch taller. Despite their similar styling, the Mercedes SUVs share only their front doors; otherwise, each has unique sheet metal.

As large as the GL may appear, it's three inches shorter than the R-Class touring wagon, which also has three rows of seating, though with less room for seven 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 is 300-600 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.