2011 Mercedes-Benz GL-Class Base GL450 4dr 4MATIC All-wheel Drive Base (A7) 7-Speed Automatic

New for 2011 is a refreshed front grille and bumpers on the Mercedes-Benz GL550, including LED taillights and daytime running lamps.Also, the 2011 Mercedes-Benz GL-Class gets an optional blind spot monitoring system, which can help the driver spot a vehicle in the next lane.

All Mercedes GL models come with a 7-speed automatic and 4MATIC full-time all-wheel drive, which distributes power to front and rear wheels equally.All GL-Class models employ air suspension for good ride comfort on a variety of surfaces and level attitude regardless of load.A full suite of safety equipment is standard across the GL-Class.

The GL-Class shares its basic platform with the ML-Class and R-Class.(Don't confuse the GL550 with the venerable G550 Gelandewagen designed for rugged terrain because the GL-Class shares nothing in common with the utilitarian G-Class beyond the GL550 engine and transmission.)

The Mercedes-Benz GL-Class is large and surprisingly capable off road yet we found it feels reasonably car-like on the road.That car-like feeling comes in part because it is built around a unibody architecture instead of traditional body-on-frame construction.The 2011 GL-Class is rated to tow up to 7500 pounds, but we recommend an American pickup truck for anything approaching that much weight.

Competitors of the 2011 Mercedes-Benz GL-Class include Audi Q7, BMW X5, Cadillac Escalade, Infiniti QX56, Lexus LX570, and Range Rover.The GL-Class offers a compelling argument of efficiency, space and features, including the ability to carry adults in the third row.Options quickly drive up the price, however.

GL350 ($60,950) and GL450 ($61,950) are similarly equipped, with MB-Tex faux leather upholstery, dual-zone climate control, power driver's seat, heated power mirrors, heated windshield washer system, reading lamps, burl walnut trim, first-row moonroof, third-row panorama roof, rain-sensing wipers, HomeLink, cruise control, six power windows, and trip computer.

Options include the Full Leather Seating Package ($1930), which includes leather upholstery, Comfort front headrests, premium interior lighting and ambient lighting; and Tri-Zone Automatic Climate Control ($1450), which includes rear air conditioning.Buyers can choose between a wood/leather steering wheel ($590) and a heated steering wheel ($225).A Class IV trailer hitch is optional ($550).Additional options include heated/ventilated front seats, Parktronic proximity sensors, running boards, lighting package (adaptive bi-Xenon headlamps with heated washers), dual-screen DVD rear entertainment system, LED daytime running lights), illuminated door sills, roof rails and metallic paint.Premium package 1 ($4,280) includes HDD navigation COMAND/voice recognition with Zagat guide, HD and Sirius radio, and MP3 inputs, power folding mirrors, power tilt/telescope steering column and driver memory, power liftgate, 115-volt outlet (house current), and auto-dimming mirrors; Premium Package 2 adds a harman/kardon Logic 7 sound system and Keyless go to all the features in Premium Package 1.

GL550 ($84,450) comes with many above options as standard, including full leather, three-zone climate control (rear air conditioning), navigation, rearview camera, Parktronic, harman kardon audio, adaptive bi-xenon headlamps, infrared-reflective glass, metallic paint, Adaptive Damping Suspension, and Keyless Go.Options are limited to a chrome package, roof cross bars, trailer hitch, rear-seat entertainment system, heated steering wheel and rear seats, illuminated door sills, and an upgrade to Nappa leather upholstery.

Safety features that come standard include eight airbags, including side airbags for all four outboard first and second-row seating positions as well as side curtain airbags that protect occupants in all three rows.GL models come with active front head restraints, LATCH tethers for child safety seats, adjustable headrests and three-point safety belts for all seating positions; make sure everyone in the vehicle always wears those seat belts because they're your first line of defense in a crash.Active safety features (to help you avoid a crash) include an Electronic Stability Program, anti-lock brakes with Brake Assist Plus, four-wheel electronic traction control, and all-wheel drive.The 2011 GL350 and GL450 come standard with run-flat tires.Optional safety features include a park-assist system, a rear-view camera and, new for 2011, Blind Spot Assist, which monitors both driver-and passenger-side blind spots.Visual and audible warnings will alert the driver when a turn signal is activated with another vehicle in either blind spot.The 2011 Mercedes-Benz GL-Class uses a proprietary Pre-Safe system, which can sense an impending collision by myriad input factors.Introduced previously on the Mercedes-Benz S-Class sedans, Pre-Safe automatically tightens the front seat belts and moves the front passenger seat to a position that can provide better protection.Side windows close to provide better support for the curtain air bags.If the system senses an impending rollover, the sunroof also closes.

The GL-Class are big vehicles.The GL is taller than the Audi Q7 and BMW X5.It's the same length as an Audi Q7, but it's nine inches longer than the BMW X5, though the BMW needs another two feet to make a U-turn than the Audi or Mercedes.Stretching to 121 inches, the Mercedes GL wheelbase is substantially longer than that of the Audi and BMW.The GL is four inches longer overall than the Range Rover and Lexus LX570.The Cadillac Escalade is 22 inches longer than the Mercedes-Benz GL-Class, and the Cadillac's wheelbase is nine inches longer.However, the GL-Class is three inches shorter than the Mercedes-Benz R-Class touring wagon, which also has three rows of seating, though with less room for six occupants.

Seen in profile, the Mercedes GL-Class features a nicely raked windshield and bulging wheel arches over large wheels (19-inches or better), which balance the proportions of a tall and long vehicle.Although tall and long, the GL-Class doesn't look as bulky as the Cadillac Escalade.Viewed from the rear, the GL offers a formidable stance.It looks tall and, though narrow for the class, it looks wide, with a large rear hatch opening and large LED tail lights, all sitting above a substantial skid plate bracketed on either side by large, rectangular exhaust pipes.

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.

Cargo capacity is one of its strengths.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.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.The load floor is flat, which is good for many cargoes.Gaps in the floor where the seats meet create holes that a dog could step in, however, which is not good.You may want to lay a board or something in there for Fido.There's room under the cargo floor for a full-size spare tire.

The interior layout is familiar to Mercedes drivers, with MB-Tex (vinyl) or real leather trim for the seats (because not all luxury car buyers want leather seating surfaces), wood trim and metal rings around gauges, air vents, and cup holders.Switchgear is comprehensive without being overwhelming, and the shift lever on the steering column and paddles on the wheel allow for maximum console space.

Second-row seats provide ample room, with more head and legroom than a Cadillac Escalade or Chevrolet Suburban offer.The rear door openings are substantial so shoes and long legs don't hit the B-pillar when climbing out.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 six-foot adults to ride back there, each in a separate seat; again with more headroom and nearly eight inches more legroom than the Escalade, and just half an inch less legroom than the much longer Suburban.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 sunroof that extends over the third row and opening quarter windows.

The COMAND system features a 6.5-inch color display screen, six-disc DVD changer, and a Bluetooth interface that allows a phone still in a pocket or purse to be operated through the audio system.COMAND can be equipped with an optional iPod/MP3 interface, Sirius satellite radio, HD radio, and an enhanced voice control system.It can play tracks stored on a data CD, DVD or SD memory card.The system can also display maps and directions for the optional hard-drive navigation system, which can be set up for SIRIUS real-time traffic info and Zagat restaurant ratings as well.

All GL-Class models can be equipped with an optional 610-watt digital harman/kardon Logic7 audio system, and a rear-seat entertainment system that includes two eight-inch screens mounted in the rear of the front-seat headrests wireless headphones and an integrated DVD player with dual-source capability.If you're in the habit of throwing your right arm behind the passenger seat when backing up, watch your rings don't scratch the screen.

The Mercedes-Benz GL550 can accelerate from 0 to 60 mph in 6.4 seconds, according to Mercedes-Benz USA.The 382-hp V8, with four valves per cylinder, generates 391 lb-ft of torque from 2800-4800 rpm with all the smoothness you'd expect in a flagship.It also generates EPA ratings of 12/17 mpg.

The GL450 is more than adequate with its 335-hp (339 lb-ft; EPA 13/17) 4.6-liter V8 if towing or speed contests aren't on your agenda; Mercedes says only a half-second longer than the GL550 (and we think their estimates are conservative).Apart from the 21-inch wheels and more aggressive bodywork, a lesser GL can be optioned to match a GL550 in features.For poor roads, winter climes that require snow chains or anyone inclined to use the low-range gear in the Off-Road package, we think the GL450 with its 19-inch wheels is a better choice than either the GL550 with its 21-inch wheels or the GL350 with its 20-inch wheels.

The GL350 uses diesel fuel rather than gasoline.The GL350's BlueTEC turbodiesel 3-liter V6 delivers 210 hp.More important is its 400 lb-ft of torque from 1600 rpm upwards.While any engine is affected by altitude, the turbodiesel will lose a smaller percentage of its power as elevation rises.The GL350 will take about two seconds longer to reach 60 mph, which it does right in line with most seven-seat hybrid SUVs.Diesels don't snap your neck from a standing start but once off the line the GL350 BlueTEC accelerates with more than adequate verve.The GL350 is also clean.The exhaust is actually cleaner than the ambient air in many smoggy areas.It rates an EPA-estimated 17/23 mpg.Our test drives have found EPA diesel ratings a bit pessimistic as we averaged better than 24 mpg in myriad conditions.Every GL-Class may be equipped to tow 7500 pounds, giving the high-mileage diesel a substantial advantage over hybrids in this respect. A 7-speed automatic transmission is standard on all GL models and operates seamlessly as an automatic.On the other hand, you can shift it yourself with paddles on the steering wheel.

The four-wheel-drive system, called 4MATIC, uses open front, center and rear differentials.Quite sophisticated, 4MATIC is designed to maintain mobility even when only wheel has traction by electronic intervention.In normal driving, the system distributes power equally to front and rear wheels.The system includes DSR, a sort of low-speed cruise control for regulating downhill speed, and Hill-Start Assist, which keeps the GL from rolling backward when launched after being stopped on an uphill slope.4MATIC also adjusts anti-lock brake controls to provide quicker stops on slippery and unpaved surfaces, an important benefit many vehicles with ABS do not offer.

Airmatic is an air suspension system that uses air bladders instead of coil springs to adjust ride height by as much as three inches, and with the GL550's adaptive damping 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, and it levels the car regardless of load for stable handling, towing and visibility.

We've driven all three GL-Class models on freeways, back roads, fire roads, and trails marked for off-highway vehicles.Steering feedback was consistent, brakes (14.7-inches in diameter on the front wheels and 13.0 inches on the rear) were responsive and consistently predictable and the GL offered nice balanced dynamic capabilities when hustled through the curves on the narrow, hilly roads that wind through the vine-covered hillsides.

The GL550's fat 21-inch tires contribute commendable grip for hard cornering.However, these wide, low-profile tires follow pavement grooves, give sharper impact sensations, have notably higher replacement costs and can not use tire chains.

New Car Test Drive correspondent G.R.Whale reported from Los Angeles.Larry Edsall contributed to this report.