The Mercedes-Benz GL 450 CDI 4MATIC, part of the X164 facelift generation produced from 2009 to 2010, represented a significant offering in the luxury SUV segment. Positioned as a high-end variant within the GL lineup, it combined a powerful diesel engine with a sophisticated all-wheel-drive system and a comfortable, spacious interior. The X164 GL, introduced in 2006, was Mercedes-Benz’s first foray into the full-size luxury SUV market, directly competing with vehicles like the BMW X5, Audi Q7, and Range Rover. The 2009 facelift brought styling updates, improved interior materials, and enhancements to the powertrain options, including the 450 CDI model.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | GL |
| Generation | GL (X164 facelift 2009) |
| Type (Engine) | GL 450 CDI (306 Hp) 4MATIC DPF G-TRONIC |
| Start of production | 2009 |
| End of production | 2010 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | SUV |
| Seats | 7 |
| Doors | 5 |
| Fuel consumption (urban) | 15.6 l/100 km (15.1 US mpg, 18.1 UK mpg, 6.4 km/l) |
| Fuel consumption (extra urban) | 9.2 l/100 km (25.6 US mpg, 30.7 UK mpg, 10.9 km/l) |
| Fuel consumption (combined) | 11.6 l/100 km (20.3 US mpg, 24.4 UK mpg, 8.6 km/l) |
| CO2 emissions | 307 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 7.6 sec |
| Acceleration 0 – 62 mph | 7.6 sec |
| Acceleration 0 – 60 mph | 7.2 sec |
| Maximum speed | 230 km/h (142.92 mph) |
| Emission standard | Euro 4 |
| Weight-to-power ratio | 8.1 kg/Hp, 123.6 Hp/tonne |
| Weight-to-torque ratio | 3.5 kg/Nm, 282.8 Nm/tonne |
| Power | 306 Hp @ 3600 rpm |
| Power per litre | 76.6 Hp/l |
| Torque | 700 Nm @ 2000-2600 rpm (516.29 lb.-ft. @ 2000-2600 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | OM 629.912 |
| Engine displacement | 3996 cm3 (243.85 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 86 mm (3.39 in.) |
| Piston Stroke | 86 mm (3.39 in.) |
| Compression ratio | 17:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | BiTurbo, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 11.5 l (12.15 US qt, 10.12 UK qt) |
| Kerb Weight | 2475 kg (5456.44 lbs.) |
| Max. weight | 3250 kg (7165.02 lbs.) |
| Max load | 775 kg (1708.58 lbs.) |
| Trunk (boot) space – minimum | 620 l (21.9 cu. ft.) |
| Trunk (boot) space – maximum | 2300 l (81.22 cu. ft.) |
| Fuel tank capacity | 100 l (26.42 US gal, 22 UK gal) |
| Permitted trailer load with brakes (12%) | 3500 kg (7716.18 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Length | 5099 mm (200.75 in.) |
| Width | 1920 mm (75.59 in.) |
| Height | 1840 mm (72.44 in.) |
| Wheelbase | 3075 mm (121.06 in.) |
| Front track | 1645 mm (64.76 in.) |
| Rear (Back) track | 1648 mm (64.88 in.) |
| Ride height (ground clearance) | 198 mm (7.8 in.) |
| Drag coefficient (Cd) | 0.37 |
| Minimum turning circle (turning diameter) | 12.1 m (39.7 ft.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 7 gears, automatic transmission G-TRONIC |
| Front suspension | Double wishbone |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Hydraulic Steering |
| Tires size | 275/55 R19 |
| Wheel rims size | 19 |
Powertrain & Engine Architecture
The GL 450 CDI was powered by the OM 629.912, a 4.0-liter V8 diesel engine. This engine was a significant achievement in diesel technology, featuring common-rail direct injection and a sophisticated bi-turbocharger system. The bi-turbo setup utilized a smaller turbocharger for quick response at low engine speeds and a larger turbocharger to maintain power at higher RPMs. The engine produced 306 horsepower at 3600 rpm and a substantial 700 Nm (516 lb-ft) of torque between 2000 and 2600 rpm. This torque output was a key characteristic, providing effortless acceleration and strong towing capability. The engine also incorporated an intercooler to further enhance performance by cooling the intake air. The transmission was a 7G-TRONIC automatic, a seven-speed unit known for its smooth shifting and efficiency. This transmission was specifically tuned to work with the characteristics of the diesel engine, optimizing gear ratios for both performance and fuel economy.
Driving Characteristics
The GL 450 CDI offered a unique driving experience for a vehicle of its size. The abundant torque from the diesel engine meant that the SUV felt surprisingly responsive, even when fully loaded. Acceleration to 60 mph was achieved in around 7.2 seconds, which was competitive for the segment. The 7G-TRONIC transmission contributed to a smooth and refined driving experience, with seamless gear changes. Compared to the gasoline-powered GL 450, the CDI model offered significantly better fuel economy and a more relaxed driving style, prioritizing torque over peak horsepower. While not as sporty as some of its competitors, the GL 450 CDI excelled in providing a comfortable and capable ride, particularly on long journeys. The 4MATIC all-wheel-drive system provided excellent traction in various conditions.
Equipment & Trim Levels
The GL 450 CDI 4MATIC typically came well-equipped with standard features including leather upholstery, power-adjustable front seats with memory function, dual-zone automatic climate control, a premium audio system, and a navigation system. Optional extras included a rear-seat entertainment system, panoramic sunroof, adaptive cruise control, and parking assist. The interior design was luxurious and spacious, with seating for up to seven passengers. The third-row seats were relatively comfortable for adults on shorter trips. Trim levels were generally standardized, with options packages allowing buyers to customize their vehicle to their preferences.
Chassis & Braking
The GL 450 CDI featured a robust chassis designed to handle the vehicle’s weight and provide a comfortable ride. The front suspension utilized a double wishbone design, while the rear suspension employed an independent multi-link setup. This configuration helped to minimize body roll and provide a stable driving experience. Braking duties were handled by ventilated discs on all four wheels, coupled with an Anti-lock Braking System (ABS) and Electronic Stability Program (ESP). The braking system was effective in providing confident stopping power, even under heavy loads. The GL 450 CDI’s suspension was tuned to prioritize comfort over outright sportiness, providing a smooth and controlled ride on various road surfaces.
Market Reception & Comparison
The GL 450 CDI was generally well-received by automotive critics, who praised its powerful engine, comfortable ride, and spacious interior. However, some reviewers noted that the diesel engine could be somewhat noisy compared to gasoline alternatives. Fuel economy was a major selling point, with the CDI model offering significantly better mileage than the GL 450. Compared to the GL 320 CDI (a smaller displacement diesel), the 450 CDI offered a substantial power increase, making it a more appealing option for those who needed extra performance. Against competitors like the BMW X5 and Audi Q7, the GL 450 CDI offered a unique combination of luxury, space, and diesel efficiency.
Legacy
The OM 629 engine family, including the OM 629.912 found in the GL 450 CDI, is known for its durability and reliability. While diesel engines generally require more diligent maintenance than their gasoline counterparts, these engines are capable of high mileage with proper care. Today, the GL 450 CDI can be found on the used car market at relatively affordable prices. Common maintenance items include regular oil changes, filter replacements, and attention to the diesel particulate filter (DPF). The GL 450 CDI remains a compelling option for buyers seeking a spacious, capable, and fuel-efficient luxury SUV, offering a unique blend of performance and practicality.
