The Mercedes-Benz G-Class Long (W463, facelift 2018) G 400d 4MATIC, produced from 2019, represents a significant evolution of the iconic G-Wagen. This variant, equipped with a 3.0-liter inline-six diesel engine producing 330 horsepower and paired with a 9G-TRONIC nine-speed automatic transmission, aimed to blend the G-Class’s legendary off-road capability with improved refinement and efficiency. The “Long” designation indicates an extended wheelbase, offering increased rear passenger space compared to the standard G-Class. This model occupied a premium position within the G-Class lineup, serving as a compelling alternative to the G 550 while offering the benefits of diesel torque and economy.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | G-Class |
| Generation | G-Class Long (W463, facelift 2018) |
| Type (Engine) | G 400d (330 Hp) 4MATIC 9G-TRONIC |
| Start of production | 2019 |
| End of production | 2019 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Off-road vehicle |
| Seats | 5 |
| Doors | 5 |
| Fuel consumption (economy) – urban (NEDC) | 10.8 l/100 km (21.8 US mpg, 26.2 UK mpg, 9.3 km/l) |
| Fuel consumption (economy) – extra urban (NEDC) | 8.9 l/100 km (26.4 US mpg, 31.7 UK mpg, 11.2 km/l) |
| Fuel consumption (economy) – combined (NEDC) | 9.6 l/100 km (24.5 US mpg, 29.4 UK mpg, 10.4 km/l) |
| CO2 emissions (NEDC) | 253 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 6.4 sec |
| Acceleration 0 – 62 mph | 6.4 sec |
| Acceleration 0 – 60 mph | 6.1 sec |
| Maximum speed | 210 km/h (130.49 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 7.3 kg/Hp, 137.7 Hp/tonne |
| Weight-to-torque ratio | 3.4 kg/Nm, 292 Nm/tonne |
| Power | 330 Hp @ 3600 rpm |
| Power per litre | 112.8 Hp/l |
| Torque | 700 Nm @ 1200-3200 rpm (516.29 lb.-ft. @ 1200-3200 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | OM 656.929 |
| Engine displacement | 2925 cm3 (178.49 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 82 mm (3.23 in.) |
| Piston Stroke | 92.4 mm (3.64 in.) |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 9.5 l (10.04 US qt | 8.36 UK qt) |
| Kerb Weight | 2397 kg (5284.48 lbs.) |
| Max. weight | 3150 kg (6944.56 lbs.) |
| Max load | 753 kg (1660.08 lbs.) |
| Trunk (boot) space – minimum | 667 l (23.55 cu. ft.) |
| Trunk (boot) space – maximum | 1941 l (68.55 cu. ft.) |
| Fuel tank capacity | 100 l (26.42 US gal | 22 UK gal) |
| Max. roof load | 150 kg (330.69 lbs.) |
| Permitted trailer load with brakes (12%) | 3500 kg (7716.18 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Permitted towbar download | 140 kg (308.65 lbs.) |
| Length | 4874 mm (191.89 in.) |
| Width | 1984 mm (78.11 in.) |
| Width including mirrors | 2187 mm (86.1 in.) |
| Height | 1969 mm (77.52 in.) |
| Wheelbase | 2890 mm (113.78 in.) |
| Front track | 1660 mm (65.35 in.) |
| Rear (Back) track | 1660 mm (65.35 in.) |
| Front overhang | 877 mm (34.53 in.) |
| Rear overhang | 847 mm (33.35 in.) |
| Ride height (ground clearance) | 241 mm (9.49 in.) |
| Drag coefficient (Cd) | 0.54 |
| Minimum turning circle (turning diameter) | 13.6 m (44.62 ft.) |
| Approach angle | 30.9° |
| Departure angle | 29.9° |
| Ramp-over (brakeover) angle | 25.7° |
| Climb angle | 45° |
| Wading depth | 700 mm (27.56 in.) |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives permanently the four wheels of the vehicle. |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 9 gears, automatic transmission G-TRONIC |
| Front suspension | Double wishbone |
| Rear suspension | Rigid axle suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
| Tires size | 275/50 R20 |
| Wheel rims size | 8.5J x 20 |
INTRODUCTION
The G 400d, introduced as part of the W463 facelift in 2019, brought a modern diesel powertrain to the G-Class lineup. Building upon the already robust and capable W463 platform, which debuted in 1979, this variant aimed to offer a balance of performance, efficiency, and the G-Class’s signature off-road prowess. The extended wheelbase “Long” version provided enhanced comfort and space, targeting buyers who desired a more luxurious and practical G-Class experience. This model represented a shift towards more refined power delivery compared to the gasoline-powered G 550, while still maintaining the G-Class’s iconic design and rugged character.
Powertrain & Engine Architecture
At the heart of the G 400d lies the OM 656.929, a 3.0-liter inline-six diesel engine. This engine is a significant departure from the V8 diesels previously offered in the G-Class, representing a move towards more efficient and technologically advanced powerplants. The OM 656 features a steel piston block, a variable-geometry turbocharger, and a common-rail direct injection system operating at pressures up to 2,700 bar. This high-pressure injection system, coupled with a sophisticated combustion process, contributes to the engine’s high torque output and relatively low emissions. The engine also incorporates a diesel particulate filter (DPF) and a selective catalytic reduction (SCR) system to meet stringent Euro 6 emission standards. The 9G-TRONIC nine-speed automatic transmission is specifically tuned to complement the engine’s torque characteristics, providing smooth and efficient gear changes. This transmission features a wide gear ratio spread, optimizing both on-road cruising and off-road crawling capabilities.
Driving Characteristics
The G 400d delivers a markedly different driving experience compared to its gasoline counterparts. The abundant low-end torque (700 Nm or 516 lb-ft) from the inline-six diesel engine provides effortless acceleration and strong pulling power, particularly useful for towing or navigating challenging terrain. While not as explosively quick as the G 550, the G 400d’s 6.4-second 0-60 mph time is still impressive for a vehicle of its size and weight. The 9G-TRONIC transmission contributes to a relaxed driving experience, with well-spaced gear ratios that keep the engine within its optimal power band. The long wheelbase enhances stability, but also slightly reduces maneuverability in tight spaces. Off-road, the G 400d excels, leveraging its permanent all-wheel-drive system, three locking differentials, and high ground clearance to conquer even the most demanding obstacles.
Equipment & Trim Levels
The G 400d Long typically came well-equipped with standard features including leather upholstery, heated and ventilated front seats, a premium sound system, and a comprehensive suite of driver-assistance systems. The interior design retained the G-Class’s utilitarian aesthetic, but with added touches of luxury and refinement. Optional extras included a sunroof, upgraded leather options, various wood or carbon fiber trim pieces, and advanced off-road packages. The “Long” designation meant increased legroom for rear passengers, making it a more comfortable option for families or those frequently carrying passengers. The infotainment system featured a large touchscreen display with navigation, smartphone integration, and a range of connectivity options.
Chassis & Braking
The G 400d utilizes a robust ladder-frame chassis, a hallmark of the G-Class design. This construction provides exceptional strength and durability, essential for off-road performance. The suspension consists of a double-wishbone setup at the front and a rigid axle with coil springs at the rear. The braking system features ventilated discs on all four wheels, providing ample stopping power. Anti-lock braking system (ABS) is standard, enhancing safety and control in various driving conditions. Given the vehicle’s weight, the braking system is designed to withstand demanding use, both on and off-road.
Market Reception & Comparison
The G 400d was generally well-received by automotive critics, who praised its blend of performance, efficiency, and off-road capability. Compared to the G 550, the G 400d offered improved fuel economy and a more accessible price point, making it an attractive option for buyers who didn’t necessarily require the V8’s outright power. However, some critics noted that the diesel engine lacked the aural excitement of the gasoline V8. Compared to other luxury SUVs, the G-Class remained a unique offering, standing out for its iconic design and unparalleled off-road prowess. Its fuel economy, while improved over previous generations, remained relatively high compared to more modern SUVs.
Legacy
The OM 656 engine family has proven to be remarkably reliable, and the G 400d powertrain is expected to offer long-term durability. On the used car market, the G 400d Long commands a premium price, reflecting the G-Class’s enduring appeal and the desirability of this specific configuration. Its combination of luxury, capability, and relative efficiency has made it a sought-after model among enthusiasts and collectors. The G 400d represents a significant chapter in the G-Class’s history, demonstrating Mercedes-Benz’s commitment to evolving this iconic vehicle while preserving its core values.
