I spent a week ripping and roaring in a GL550, and my conclusions are mixed. The SUV's inconsistent acceleration obstructs an otherwise impressive driving experience, and issues with visibility and control usability sour the well-tailored cabin. Most troubling, though, is the GL's poor reliability record, which is tempered only by the fact that its competitors don't fare much better. The Benz has enough strengths that it might prove a worthy family-hauler, but be sure to consider its limitations before you buy.
Shortly after last year's GL450 arrived, Mercedes introduced a diesel GL320 CDI; click here to compare the 2008 GL-Class with the 2007 model. Thanks to the higher efficiency of its diesel engine, the CDI's mileage is considerably better than its V-8 gas siblings, but because of stricter emissions standards the diesel isn't available in California and several northeastern states. (For 2009, a cleaner GL320 Bluetec version will be available nationwide.) All GL-Class models include full-time four-wheel drive. Here's how the engines compare:
|Engine||3.0-liter V-6||4.6-liter V-8||5.5-liter V-8|
|Horsepower (@ rpm)||215 @ 3,800||335 @ 6,000||382 @ 6,000|
|Torque (lbs.-ft. @ rpm)||398 @ 1,600 — 2,800||339 @ 2,700 — 5,000||391 @ 2,800 — 4,800|
|Gas mileage (mpg, city/hwy.)||18/24||13/18||13/17|
|Required fuel||Diesel||Premium gas||Premium gas|
|Source: Automaker data for 2008 models.|
The GL550's 5.5-liter V-8 sees duty across a number of other Mercedes models. It's a powerful engine, mustering enough torque to propel the SUV to freeway speeds with ease. A seven-speed automatic is the standard transmission for all engines. Gear hunting is minimal, and downshifts can come two or three gears at a time — from sixth to third, for example. The resulting shorter ratios for each gear allow quick, confident bursts of power.
Unfortunately, starting out can be troublesome. A few days into my test drive, I began to notice some significant accelerator lag. It wasn't apparent during stop-and-go driving, but a sudden need for power — escaping from a slow-moving freeway lane, for example — was sometimes met with a lazy response. I try to tolerate some accelerator lag, as it's largely a byproduct of the electronic throttles that most cars, including the GL, employ these days. What frustrates me is inconsistent response, and that's what this SUV exhibits. Sometimes the gas pedal proved virtually lag-free, while other times it took a half-second or longer to summon the appropriate acceleration. Mercedes spokesman Rob Moran said the way Mercedes tunes its accelerators — which generally require more pressure than a typical car's — might have something to do with it.
Antilock brakes with discs at all wheels are standard. The pedal delivers strong response, but it's a bit touchy when you lift back off, so smooth stops may take practice.
Ride & Handling
The GL has a unibody frame — rare among full-size SUVs — and its four-wheel-independent air suspension swaps traditional coil springs for inflatable air bladders. Its ride height can be varied to enhance high-speed stability or offroad ground clearance. An optional adaptive suspension constantly adjusts ride stiffness as conditions require. My test car came equipped with the system, which, combined with its 21-inch wheels and sporty P295/40R21 tires, resisted body roll admirably.
Like many adaptive suspensions, the GL550's has Sport and Comfort modes that yield stiffer or softer response, respectively. There's also an Auto mode that calibrates the settings somewhere between those two. Sport mode resists body roll marginally better than Comfort, but the difference is slight. On the highway, the differences are all but unnoticeable.
The steering wheel's precise turn-in makes curvy roads a pleasure to drive. There's enough power assist at lower speeds for tight parking-lot maneuvers, though at times I found lumpy pockets of resistance while navigating our downtown parking garage. It's a noticeable difference from the steering response at higher speeds, which is smooth and confidence-inspiring.
Alas, the GL550's advanced suspension can't make up for the brittle ride quality of its thin 40-series tires. You'll hear and feel every highway expansion joint, while potholes and speed bumps become a jarring, noisy experience. Most annoying was the abundance of suspension reverberation I felt around Chicago's roughed-up streets: No matter what setting I had it on, major bumps sent palpable motions through the entire chassis for a half-second or more.
On smoother roads — that's you, California — the ride feels more agreeable. Tire noise is still noticeable, but wind noise is minimal and the engine is nearly silent. I can only presume that the GL320 and GL430, with their 18-inch wheels and thicker P265/60R18 tires, would be more comfortable on bumpy roads, but be sure to compare them on your test drive.
At 39.7 feet, the GL's turning circle is competitive with its peers.
Exterior & Styling
Particularly from the rear, the GL's appearance looks a bit like Mercedes' original M-Class. The 21-inch wheels, oversized grille and chrome running boards on my test car gave it a look similar to that of Mercedes' AMG performance cars — perhaps that was the intention, given that there is no AMG GL-Class — and should secure the car a front-row spot at most valet stands.
Less-expensive GLs have 18- or 19-inch wheels. An optional offroad package on the GL450 raises the air suspension to yield 12 inches of ground clearance — some 2 inches higher than a Hummer H2's. The package also has a two-speed transfer case and locking center and rear differentials.
If the cockpit in a Cadillac Escalade or Infiniti QX56 feels like a roomy lounge, the GL550's cabin is eminently more carlike. Don't expect massive armrests and a tall dashboard — rather, the wraparound dash and narrower seats could pass for those in a luxury sedan. The quality is good: Upper portions of the dashboard come wrapped in leather, and wood and chrome inlays effectively offset the lower panels. Nearly every surface is soft to the touch, including areas the driver's and front passenger's knees might knock against. Nice. Fit and finish is respectable, save for two unsightly gaps: one around the glove compartment, the other bordering the steering wheel hub.
The center controls look and feel high-quality, and it's nice to see Mercedes has stuck with black plastic where other carmakers have painted theirs tacky-looking silver. I'm not as keen on the navigation system. It uses Mercedes' Comand interface, which has proved handy in other Benzes I've driven, but this is an earlier generation with second-rate graphics, and it has to be used with tiny buttons alongside the screen. Good news: The 2009 GL-Class offers an updated system that doesn't use those buttons; I checked it out in an '09 GL320 Bluetec at an auto show, and it's a major improvement.
Blind-spot visibility is generally good, but most Cars.com staffers who drove the GL thought the tiny side mirrors were a joke.
Seating & Cargo
The GL550's front seats have a litany of power adjustments, including adjustable stiffness for the side bolsters. Even with the bolsters and lumbar support dialed all the way back, the seats are too stiff. That's typical in German cars, but in a large SUV I prefer cushier seats. These hold you in place during spirited driving; expert road manners notwithstanding, I'm not sure many GL-Class drivers are going to carve corners.
I compared seating in a GL-Class, QX56, Escalade and Lexus LX 570 at an auto show, and the front seats of all three competitors suited me better. Second-row space in the GL550 seems on par with the competition — I'm about 6 feet tall, and I had no complaints — but it's the third row that shines. Legroom and headroom are leagues better than the others', and the GL's seats sit high enough that passengers aren't watching their knees. The Lincoln Navigator is perhaps the only competitor that has as much third-row roominess. As craftsmanship goes, there is no competition: The GL550's third row boasts reading lights, overhead A/C vents, a fixed skylight and leather-wrapped armrests. It puts third-row décor in the other SUVs to shame.
All trim levels have a power-folding 50/50-split third row. It folds more or less flat, as does the second row, and the resulting load floor is free of any major gaps. Maximum cargo volume is 83.3 cubic feet, which considerably trails some of the GL's boxiest competitors.
|Cargo Volume Compared (cu. ft.)|
|Max. seats||Behind 3rd row||Behind 2nd row||Behind 1st row|
|Lexus LX 570||8||15.5||41.0||83.1|
Source: Automaker data for 2008 models.
Safety & Reliability
As of this writing, the Insurance Institute for Highway Safety has not yet crash-tested the GL-Class. Eight standard airbags include three-row side curtain airbags and seat-mounted side-impact airbags for the first and second rows. Active head restraints, all-disc antilock brakes, traction control and an electronic stability system are also standard.
With Latch child-seat anchors for the outboard second- and third-row seats, don't be surprised if you're drafted to schlep the entire neighborhood's tots to daycare. The second row has top-tether anchors for all three seats, and they're conveniently mounted midway down the back of the seats. Parents should note that all the anchors have removable plastic covers. They're a pain in the neck to pry off, so here's betting you'll leave them off — and lose them over time.
Poor reliability is the GL's biggest drawback. In its first year on the market, the SUV earned the worst possible score, Much Worse Than Average, from Consumer Reports. The publication cited power accessories as the GL's biggest trouble spot. I'd be more concerned if large luxury SUVs weren't generally such a reliability abyss; the Escalade earned dismal CR scores, and although the publication didn't have sufficient data to rate the Range Rover or QX56 in 2007, both SUVs scored poorly in prior years. The Navigator is the one bright spot, with a CR rating of Better Than Average. The redesigned LX 570 hasn't been on the market long enough to gauge.
Features & Pricing
Excluding the destination charge, the GL320 starts at $53,400, while the GL450 starts at $55,900. Standard features on both include four-wheel drive, faux leather upholstery, a CD player with an auxiliary MP3 jack, dual-zone automatic climate control, a fixed third-row skylight, and heated, power-adjustable front seats. The GL550 hikes the price considerably ($77,375), but it comes stocked with standard features: larger wheels, a moonroof, leather, a backup camera, heated second-row seats, Harman Kardon audio, xenon headlights and a navigation system. Many of those features are optional on lesser trims.
GL550 options include keyless access (it supplements the regular keyless entry) and a rear-seat DVD system. Fully loaded, the GL-Class tops out around $83,000.
GL-Class in the Market
The GL's price spread gives it a wide range of competitors: At the low end it competes with Infiniti and Lincoln, and at the high end there's Lexus and Land Rover. It seems less suited for the higher-tier competition, as its ride quality and control interface stop it short of luxury-SUV perfection, but as an alternative to some of its less-expensive competitors, the GL holds promise. It's elegantly tailored, stylish and roomy, and for some families it could prove a worthy steed. Sales have been steady so far, but whether or not enough folks will be willing to look past the GL's annoyances to make it a success — particularly with $3.50-per-gallon gas — remains uncertain.
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