2007 Mercedes-Benz GL450

2007 Mercedes-Benz GL450 2007 Mercedes-Benz GL450
First Drive Review

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.

Conversely, the controls are mostly familiar, with two large gauge pods straight ahead, the same four-spoke steering wheel, and a familiar center stack. However, the GL has additional wood accents and a soft, leather-like dash with exposed stitching that improves on the sea-of-gray-plastic look found in some entry-level ML350s. The second row is a 60/40-split bench offering 55 cubic feet of space-plenty of room for six-plus-footers. That bench flips forward (only on the passenger side) to access the two-person third row that has almost nine more inches of legroom than the Escalade's and more headroom back there than in both American competitors.

There are 11 cubic feet of cargo space available behind the third row, but if you don't need to seat seven, the second row and the power-operated third row fold flat, exposing 83 cubic feet.

Naturally, there's no shortage of optional equipment to bump the GL450's price as much as $25,000 above the likely $55,000 starting point, including a rear entertainment system with two seven-inch screens, a power liftgate, DVD navigation, stereo upgrades, parking assist, active cruise control, and a two-speed transfer case.

In contrast with the somewhat slow-selling, minivan-looking R-class sport-ute, the GL fits into a popular and well-established market segment. Sure, it's luxurious inside, and the cachet of the three-pointed star is a given. Beyond that, what should really make the opposition wary is the GL450's roomy interior combined with a competitive price and above-average power.