In January 2006, the Mercedes-Benz GL-Class from model series X 164 made its début at the North American International Auto Show (NAIAS) in Detroit, Michigan. The vehicles were initially available on the US market from spring 2006, while they could be ordered in Europe from February 2006. Deliveries to the local markets started in September. The utility vehicles positioned in the "full-size SUV" segment were manufactured together with the technically related M-Class models from model series W 164 and the R-Class from model series 251 at the Mercedes-Benz plant in Tuscaloosa, Alabama.
The premium SUV, which was optionally available with seven seats, already documented its claim to leadership within the market segment in its visual appearance. The exterior design was characterised by smooth body surfaces paired with powerful, wedge-shaped design elements and striking detail solutions. The overhangs at the front and rear were short as is typical of all-terrain vehicles. The front of the car was characterised by a vertical radiator grille with a central star and two generously dimensioned silver horizontal louvres with wide chrome plating. Two sleekly modelled power bulges characterised the high-set bonnet.
Overall, the body proportions harmonised well with a length of 5088 mm, a width of 1920 mm and a height of 1840 mm. In the side view, the long wheelbase, a beltline starting in front of the front wheel arch and rising at an angle towards the rear, and the high roofline stretching to the rear wall created a dynamic silhouette. Solid side rub strips in combination with sturdy roof railing further structured the appearance of the vehicle flanks. Large glass areas ensured good all-round visibility and brightness in the interior, with the upright D-pillar conveying a classic off-road vehicle look.
The tall rear end was divided by horizontal creases that emphasised the width. The latter also applied to the design of the voluminous, high-set rear bumper, the chrome handle strip in the tailgate and the chrome-plated exhaust tailpipes with a rectangular cross-section positioned far to the outside.
In the interior, high-quality materials combined with first-class style created a prestigious ambience. A characteristic feature above all was the significantly more spacious interior compared to the ML models: Up to seven passengers could be accommodated in the GL-Class – with ample space in every respect. The two individual seats in the third row, which could be lowered into the load compartment floor, were also full-fledged seats. If there was less need to transport people, these could be lowered separately or together electrically at the touch of a button, creating a completely flat loading area with a load compartment length of up to 2128 mm and a maximum transport capacity of 2300 litres.
The dashboard and interior door panels were characterised by a smooth surface design with a colour separation into a leather-trimmed dark upper area and a lighter lower area. A continuous wooden trim element emphasised the impression of width and spaciousness. The cockpit of the new GL-Class was dominated by two slanted instrument clusters positioned in two tubes and surrounded by fine chrome rings, and by a four-spoke multifunction steering wheel with aluminium look on the lower spokes. The centre section of the instrument panel featured ergonomic controls and displays. The sturdy centre console with stowage compartments and integrated cup holder function as well as two sturdy, longitudinally arranged grab handles, which provided additional support when driving off-road, organically adjoined this.
In keeping with their positioning in the premium SUV segment, the GL-Class vehicles were comprehensively equipped. Among other things, the THERMATIC automatic climate control system in the GL 320 CDI 4MATIC and the THERMOTRONIC with multi-zone control in the V8-powered GL 420 CDI 4MATIC, GL 450 4MATIC and GL 500 4MATIC models were included as standard, as were ARTICO upholstery combinations, fully electrically adjustable front seats and a panoramic roof above the third row of seats.
At market launch, the GL-Class was available in four model variants – two diesel- and two petrol-powered models. All of them ensured a high level of driving comfort and appealing driving performance: The entry-level model was the GL 320 CDI 4MATIC, which was powered by the familiar 165 kW/224 hp 3.0-litre V6 of the OM 642 diesel engine series. The second diesel model, the GL 420 CDI 4MATIC, was positioned well above it. It was powered by the 4.0-litre V8 diesel OM 629, which delivered 225 kW/306 hp and a maximum torque of a stout 700 Nm. Both diesel engines undercut the limits of the Euro 4 emissions standard and operated with maintenance-free diesel particulate filters.
The GL 450 4MATIC and GL 500 4MATIC petrol models were equipped exclusively with eight-cylinder engines. In the former, a version of the modern M 273 engine family with a displacement of just under 4.7 litres celebrated its world première. The engine, which featured a square bore/stroke ratio, four overhead camshafts and four-valve technology, was calibrated to 250 kW/340 hp. In contrast, the 5.5-litre version of the engine with 285 kW/388 hp familiar from the new S-Class from model series 221 was used in the GL 500 4MATIC. Both V8 petrol engines also fell below the strict Euro 4 limits and showed favourable average standard fuel consumption values in the range of 13 to 14 litres per 100 km in a class comparison. The seven-speed automatic transmission 7G-TRONIC with DIRECT SELECT operation was fitted as standard in all models.
Despite the unladen weights of the GL models of around 2500 kg, all engines ensured superior driving performance: The GL 500 4MATIC held the top position here with an electronically governed maximum speed of 240 km/h. An important factor in this regard was the good aerodynamics given the vehicle dimensions with a drag coefficient of 0.37, which also contributed to the moderate fuel consumption figures.
Similar to the M-Class, which was positioned below it in the model hierarchy, the GL-Class also utilised all the advantages of a unibody construction in terms of passive safety. The highly stable passenger cell, together with the front and rear deformation zones, formed an efficient foundation for the occupant protection systems. These included adaptive, two-stage airbags for the driver and front passenger, side airbags at the front and optionally in the centre row of seats, window airbags across all three rows of seats from the A-pillar to the D-pillar, three-point seat belts on all seven seats, belt tensioners and adaptive belt force limiters for the driver and front passenger as well as belt tensioners and belt force limiters on the outer seats of the centre row. The comprehensive safety package was supplemented by the crash-responsive NECK-PRO head restraints for the driver and front passenger, which were available as an option.
With the PRE-SAFE® anticipatory occupant protection system, which could also be specified as an option and was realised for the first time worldwide in this market segment, Mercedes-Benz raised the safety level of the GL-Class to new heights. PRE-SAFE® uses the sensors of dynamic driving control systems such as ABS, BAS Brake Assist and the Electronic Stability Program ESP® to optimise the protective effect of the passive safety elements in hazardous driving situations. Pedestrian protection was also a particular focus during the development of the GL-Class. In the area of the front end, for example, defined clearances between the body and the major assemblies underneath allowed for large deformation paths. This, in combination with yielding impact zones, resulted in a high protection potential for pedestrians and cyclists.
The utility vehicles of the GL-Class demonstrated not only the virtues typical of Mercedes-Benz off-road vehicles, such as outstanding solidity, robustness and durability, but above all convincing handling quality on and off the road. 4MATIC permanent all-wheel drive in combination with the AIRMATIC air suspension as standard and the ADS adaptive damping system, which also came as standard, offered surprisingly agile handling – despite a wheelbase of 3075 mm. Thanks to ESP® trailer stabilisation, the GL models also proved to be particularly suitable towing vehicles. This special assistance system defuses critical driving situations with trailers by means of targeted braking interventions.
All GL-Class models had features such as downhill driving assist, start-off assist and off-road ABS as standard to provide support when driving off road. In addition, a technology package called "Offroad-Pro" was included as standard in all models offered in the ECE area to further hone their off-road capabilities. It was specifically designed for tackling particularly challenging off-road passages and included a two-speed transfer case with off-road reduction and 100% differential locks for the transfer case and the rear axle. The Offroad-Pro Package was supplemented by an AIRMATIC modified for more demanding use, which allowed the ground clearance to be increased to up to 307 millimetres and the fording depth to be increased to 600 mm.
At the time of its market launch in Germany in early autumn 2006 the gross list prices ranged from € 63,684.00 for a GL 320 CDI 4MATIC to €85,898.00 for a GL 500 4MATIC. The GL 420 CDI 4MATIC and the GL 450 4MATIC were positioned in between with prices of € 79,460.00 and € 77,604.00, respectively.
As part of the diesel initiative launched by Mercedes-Benz in the USA, the new "Vision GL 420 BLUETEC" concept vehicle was presented at the Detroit Motor Show in January 2007 as the successor to the "Vision GL 320 BLUETEC" shown the previous year. The premium SUV was primarily intended to demonstrate to the North American market that BLUETEC®, the modular exhaust gas purification system for diesel engines, could be used to achieve economical fuel consumption and a sustained reduction in pollutant emissions even in decidedly powerful vehicles. Powered by the 4.0-litre OM 629 V8 diesel engine rated at 216 kW/294 hp, which not only met customer expectations in terms of superior power delivery, but also complied with the strict emissions regulations, Mercedes-Benz stated an expected average fuel consumption for the concept vehicle of 9.8 litres per 100 km.
The appearance of the Vision GL 420 BLUETEC was visually bolstered by an even more strikingly swept-back front with a dominant radiator grille, wide flared wings, stately 21-inch wheels and running boards.
A few months later, in summer 2007, Mercedes-Benz presented the version of the "Vision GL 320 BLUETEC" concept vehicle tailored to the European market. However, the BlueTEC technology once again saw its market launch in North America, where it was first used as standard in the GL 320 BlueTEC ("BlueTEC" now in the new spelling) from autumn of the following year. The 3.0-litre V6 of the OM 642 engine series, which was the power unit here, was now tuned to 155 kW/211 hp and provided a torque of 540 Nm. For the best possible minimisation of nitrogen oxide emissions in particular, the BlueTEC technology package included AdBlue injection and a downstream SCR catalytic converter. This means that the export model fulfilled the strictest emissions regulations worldwide. In addition, the GL 320 BlueTEC consumed just 9.5 litres of diesel fuel per 100 kilometres, which, depending on the usage profile, equated to a consumption advantage of between 20 and 40 % over a comparable petrol-powered full-size SUV.
By the time of the first facelift in spring 2009, clearly structured production figures of the GL-Class models had emerged. The GL 450 4MATIC, with its superior V8 petrol engine and a displacement of around 4.7 litres, accounted for the lion's share of customer demand, with almost 62,000 units sold. The GL 320 CDI 4MATIC, which rounded off the lower end of the range, took second place in the production statistics with around 22,000 vehicles, followed by the top-of-the-range GL 500 4MATIC with just over 18,000 units. In contrast, the most expensive model in the series proved to be much less popular: Only around 6,500 vehicles of the diesel-powered GL 420 CDI 4MATIC were produced in the period under review.
