About four years ago, Mercedes started working behind the scenes on a full-size sport-ute, the 2007 GL. That wasn't a surprising move considering the company had observed that about 25 percent of first-gen M-class owners were ditching their Benzes to buy other manufacturers' larger luxury SUVs.
Mercedes is no SUV slouch, remember. In 1997, it practically got the mid-size luxury-SUV ball rolling with the M-class. We compared the ML320 with nonluxury brands such as Jeep and Toyota since Acura, BMW, and Lexus had yet to field entries.
And now that the mid-size segment is bursting with high-end choices, other automakers are adding full-size, mid-$50, 000 models. The well-established players are Cadillac and Lincoln, which sell roughly 70, 000 of these luxury barges - the Escalade and the Navigator - each year. Newer entries include Infiniti's QX56, around for just over two years, as well as the seven-passenger Audi Q7 that will launch in June, a month after the GL.
Now, don't confuse the GL with the 26-year-old G-class (Geländewagen), originally designed for the German Army, that starts at more than $80, 000. The GL is built alongside the five-passenger M-class and six-passenger R-class at the company's plant in Tuscaloosa, Alabama. Some 60-to-70 percent of GL production (about 25, 000 units) is slated to be sold in the U.S.
As you may have guessed by now, the GL shares many parts with the R- and M-class SUVs - on the order of 70 to 80 percent. All three have unibody frames, independent suspensions (control arms in front and a four-link setup in back), an excellent seven-speed transmission, and all-wheel drive.
Although the GL is Mercedes' most spacious product, its 121.1-inch wheelbase roughly splits the difference between those of the M- and R-classes. It's not the longest or widest of the trio, but the GL's 72.4-inch roofline is the highest and makes for more headroom than comparable positions in either the M or R.
Initially, the only engine offered is a 4.7-liter V-8 that is a derivative of the 5.5-liter in the S550 sedan. It's a new member of the DOHC four-valve-per-cylinder family and makes 335 horsepower and 339 pound-feet of torque - 33 more horsepower and the same amount of torque as the old SOHC 5.0-liter V-8 found in the ML500 and R500. We've found both of these new engines to be extremely quiet and smooth, and the free-revving 4.7-liter energetically tugs the 5300-pound GL450 (it will somewhat less energetically tow 7500 pounds, 100 more than an Escalade).
With a better power-to-weight ratio than both the ML500 and R500, we expect 0-to-60 times in the mid-six-second range for the GL450. Beating the 403-hp Escalade isn't likely, but acceleration times probably aren't the deciding factor for buyers in this segment. However, in about a year, Mercedes will add a GL550, with the 382-hp V-8 from the S-class. At this time, there's no plan for a horsepower-monster AMG model, says Mercedes, but a 45-state diesel option will launch before year's end.
The GL rides on standard 18-inch wheels, with 19s and 20s available. It also comes with Mercedes' height-adjustable Airmatic suspension, which is optional on the M- and R-classes. In this case, the air springs soften the reflexes of the big SUV, riding noticeably smoother than its M- and R-class siblings. Sure, there's more body roll, but the GL is plenty competent in its segment. For now, it's too close to call how it matches up to the much-improved Escalade and the Navigator has a lot of catching up to do. The GL's steering is precise if a touch heavy, but the biggest annoyance is a vague brake-pedal feel. Considerable dead travel causes initial confusion, and even after pads meet rotors, modulation isn't confident. Every M- and R-class we've driven has had this issue.
It's wise, we think, that the GL isn't simply a larger copy of the M-class. In fact, the only shared sheetmetal is the front doors. The GL's styling is more conservative, with a tall, broad profile and much softer shapes than the ML's creases. Two thick chrome bars across the grille as well as differently shaped head- and taillights further distinguish it from the ML.