2007 Mercedes-Benz GL-320 CDI V6 Review

The Mercedes-Benz GL-Class is a genuine four-wheel drive that is at home in Toorak or Double Bay as it is in the Simpson Desert. It is more likely to be found in the former, but the silly thing is that the GL is such a competent off-roader that it is a shame that the majority of those who purchase it may never experience its true capabilities. Along with genuine 4x4 ability, this wagon has an enviable carrying capacity with a cargo area that easily dwarfs that of a LandCruiser or Patrol. The GL-Class is the big daddy of the Mercedes off road range and arrived late last year after previewing at the Sydney Motor Show in October. The GL-Class is a big vehicle, which contributes both to its strength and provides ammunition for its detractors. It is the third in a brand line-up of up market four-wheel drives launched by Mercedes-Benz in 2006. These being the R-Class crossover wagon and the second-generation M-Class.

The GL-Class is, well in a class of its own in the Mercedes family, being the biggest vehicle by far, and offering genuine 4WD capability in an impressive and luxurious package. The word 'big' crops up a lot when discussing the GL-Class and at 5.08 metres long and weighing almost 2.4 tonnes it is a seriously comprehensive vehicle. While first impressions are, wow, this thing is big; spend some time with it and it seems to retreat in size, but certainly not stature. It is powered by a choice of V6 turbo-diesel or 5.5-litre V8 petrol engines. Our test vehicle was the entry level GL320 CDI 3.0-litre turbo-diesel V6, which delivers 165kW of power at 3800rpm and peak torque of 510Nm at 1600-2800rpm. The GL uses a monocoque bodyshell design, air suspension and in this case, the excellent seven speed automatic transmission.

After some initial apprehension, really about the bulk of the vehicle in fast moving lanes of traffic, the GL becomes a fantastic touring machine and certainly once on the open road is an effortless tourer. Around town I had little trouble with the GL as the driver has a commanding view and the steering is so good that manoeuvring the wagon really isn't an issue. There is much that impresses with the GL320, not the least being the 3.0-litre turbo-diesel engine. This gem is a real beauty, and considering the vehicle mass it needs to move around, it does the job easily and without any fuss. Similarly the seven speed transmission is first class. The engine is an excellent unit with a generous band of torque that propels the vehicle forward with power on tap. Acceleration is impressive and when pushed has excellent response. If pushed a lot, the GL can double Australia speed limits, although I didn't personally pursue confirmation of this information.

For a vehicle of this size one would expect loads of body roll and handling to be a little untidy, but again the GL comes out trumps. This can largely be attributed to the air suspension, which delivers first class stability and ride comfort aided by a strong arsenal of technology. These include 4Matic full time 4WD together with the standard Airmatic suspension, precise speed-sensitive power steering and adaptive damper systems, and traction control. All GL models are equipped with Mercedes Off Road Pro engineering package, which features Downhill Speed Regulation (DSR), hill-start assist and off-road ABS assist to help the GL-Class driver off-road. The GL-Class is equipped with a two-speed transfer case with a low range ratio and 100 percent differential locks for the transfer case and the rear axle. The modified Airmatic air suspension, designed specifically for the more demanding conditions, in-creases the ground clearance to a maximum of 307 millimetres where required, and raises the fording depth to 600 milli-metres.

The air suspension provides three off road levels, which are selected by a dial on the dash. At highway speeds the suspension is set at its lowest position. At level 1 the body sits 30mm above highway level. Level 2 is for off road driving and raises the vehicle 80mm above highway level. For extremely rough terrain level 3 raises the vehicle 110mm above the highway level. This level can only be maintained at speeds up to 20km/h and once exceeded drops back to the previous level. At level 3 the approach angle is 33 and the departure angle at 27 with a fording depth of 60cm. From highway to winding mountain roads the GL Class proved a great vehicle, with ride and handling through twisty sections, above the recommended pace both easy and very assured, with no discomfort for occupants as the combination of stability control, self levelling, anti-dive and adjustable dampers keeping the vehicle level and handling first rate. For a large vehicle it handles challenging roads remarkably well and is surprisingly nimble.

It is well weighted and body roll is subtle, rather than noticeable. Once we left the bitumen and tackled some bush tracks, the GL 320 showed another side to its armoury. While this vehicle can be used as a luxury tourer or people mover, it is also an extremely capable four-wheel drive. Again the suspension soaks up ruts and bumps with aplomb, whereas the drive is apportioned 50:50 to all four wheels. The 320 has three differentials, a specially calibrated 4ETS electronic traction control system, Hill Descent Control and additional low range gearing to ensure positive traction. Encounter a log or rocky outcrop and it is simply a case of raising the suspension setting and traversing the obstacle. With track closures still in place we could find no track that caused the big German the slightest problem. While the GL-Class has all the hardware to tackle challenging terrain, it remains a luxury wagon that comes with a comp-rehensive equipment list. Perhaps the toughest call is $3,400 extra for two additional seats to convert the wagon into a seven seater. The GL320 is priced at $103,900. There is an inexplicably large jump to $146,900 for the flagship GL-500 V8 petrol version. As expected, the cabin is roomy with plenty of head and leg room.

Front bucket seats are generously wide with power adjustments for head restraint & seat cushion angle, height, backrest angle and fore/aft adjustment. Our seat also had adjustments for spinal curve and lumbar support plus side cushions. In five seat form the wagon has an enormous 1240 litres of luggage space, a large centre storage console and the usual storage bins, cup holders, etc. The dash is very similar to the ML Class and the media centre has menus for vehicle operations (eg trip meters, digital speedo, outside temperature), audio, navigation and off-road (vehicle height, compass, state of diff locks). The seven speed auto is well matched to the 3.0-litre turbo-diesel and there are steering wheel paddles for manual gear selection. In most cases 'Drive' is adequate. The gearshift offers sport and manual gearshift programs. Ride comfort can also be selected with auto delivering a soft and wallowing style of ride. The "sport" setting sharpens things up a little, and while slightly harder delivers a more tidy ride. Standard equipment is generous, with few omissions - with those that are - available as extras. The most glaring omission is the lack of a decent spare wheel. For a full size 4WD wagon not to have a matching spare is ridiculous.

The GL320 CDI turbo-diesel V6 offers excellent value and provides a multi-purpose vehicle that can be whatever you want it tp be. Whether towing, touring or a night out, the GL is up for it. Finally, despite some spirited touring the diesel returned just over 10 litres per 100kms, which is very reasonable. The GL-Class is a classy performer, which is not for everyone, but for those desirous of a roomy wagon with plenty of comfort and luxury appointments, the GL320 is a worthy contender.
Brian Tanner

Specifications: Mercedes-Benz GL-320 CDI
Engine
Type: 3.0-litre, DOHC, 224-valve, V6 turbo-diesel
Displacement: 2987cc
Max. Power: 165kW @ 3800 rpm
Max Torque: 510Nm @ 1600-2800 rpm
Max. speed: 210km/h

Transmission
Type: Seven speed automatic, all-wheel drive with low range reduction

Suspension
Front: Double wishbones, anti-dive, adjustable air springs, adjustable dampers, stabiliser bar.
Rear: Four-link suspension, anti-squat and anti-dive, adjustable air springs, adjustable dampers, stabiliser bar

Steering
Type: Rack and pinion power steering.
3.3 turns lock to lock
Turning circle: 12.1 metres

Brakes:?Ventilated front and rear discs, ABS with EBD and BAS

Wheels &?Tyres: 18 x 8.0 alloy wheels, tyres 265/60 R18. Space saver spare

Safety equipment
Dual front and side airbags, rear side airbags, window airbags, ABS with EBD and brake assist, traction control,
stability control, height adjustable headrest all round, lap-sash seat belts, tyre pressure monitor

Dimensions &?capacities
LxWxH: 5088 x 2127 x 1840-1950mm
Ground clearance: 307 mm
Overhang, front/rear: 870/1143 mm
Angle of approach/departure: 33/27
Ramp angle: 23 degrees
Fording depth: 600 mm
Slope climbing ability: 100 percent
Tilt angle: 35 degrees
Turning circle: 12.1 m
Ave. fuel consumption: 9.8-litre/100km
Fuel tank: 100 litres