The Mercedes-Benz GLS 350d (X167, facelift 2023) represents a significant iteration of the full-size luxury SUV, introduced in September 2023. Positioned as a mid-range offering within the GLS lineup, it combines diesel efficiency with mild-hybrid technology and the renowned 4MATIC all-wheel-drive system. This variant caters to buyers seeking a spacious, comfortable, and capable SUV with a focus on long-distance cruising and towing capacity. It builds upon the foundation of the X167 generation, which debuted in 2019, incorporating styling updates and technological enhancements with the 2023 facelift.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | GLS |
| Generation | GLS (X167, facelift 2023) |
| Type (Engine) | GLS 350d (313 Hp) Mild Hybrid 4MATIC 9G-TRONIC |
| Start of production | September, 2023 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | SUV |
| Seats | 7 |
| Doors | 5 |
| Combined fuel consumption (WLTP) | 8-9.1 l/100 km (29.4 – 25.8 US mpg, 35.3 – 31 UK mpg, 12.5 – 11 km/l) |
| CO2 emissions (WLTP) | 210-240 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 6.7 sec |
| Acceleration 0 – 62 mph | 6.7 sec |
| Acceleration 0 – 60 mph | 6.4 sec |
| Maximum speed | 238 km/h (147.89 mph) |
| Emission standard | Euro 6e |
| Weight-to-power ratio | 8.1 kg/Hp, 123.2 Hp/tonne |
| Weight-to-torque ratio | 3.9 kg/Nm, 255.9 Nm/tonne |
| Battery voltage | 48 V |
| Battery technology | Lithium-ion (Li-Ion) |
| Electric motor power | 20 Hp |
| Electric motor Torque | 200 Nm (147.51 lb.-ft.) |
| Electric motor location | Between the combustion engine and the transmission |
| Power | 313 Hp @ 3600-4800 rpm |
| Torque | 650 Nm @ 1350-3200 rpm (479.42 lb.-ft. @ 1350-3200 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | OM 656.830 |
| Engine displacement | 2989 cm3 (182.4 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Compression ratio | 15.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 8.5 l (8.98 US qt | 7.48 UK qt) |
| Coolant | 17.2 l (18.18 US qt | 15.13 UK qt) |
| Kerb Weight | 2540 kg (5599.74 lbs.) |
| Max. weight | 3300 kg (7275.25 lbs.) |
| Max load | 760 kg (1675.51 lbs.) |
| Trunk (boot) space – minimum | 355 l (12.54 cu. ft.) |
| Trunk (boot) space – maximum | 2400 l (84.76 cu. ft.) |
| Fuel tank capacity | 90 l (23.78 US gal | 19.8 UK gal) |
| AdBlue tank | 31.6 l (8.35 US gal | 6.95 UK gal) |
| Max. roof load | 100 kg (220.46 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 | 5209 mm (205.08 in.) |
| Width | 1956 mm (77.01 in.) |
| Width including mirrors | 2157 mm (84.92 in.) |
| Height | 1823-1928 mm (71.77 – 75.91 in.) |
| Wheelbase | 3135 mm (123.43 in.) |
| Front track | 1669 mm (65.71 in.) |
| Rear (Back) track | 1692 mm (66.61 in.) |
| Front overhang | 938 mm (36.93 in.) |
| Rear overhang | 1136 mm (44.72 in.) |
| Ride height (ground clearance) | 175-290 mm (6.89 – 11.42 in.) |
| Minimum turning circle (turning diameter) | 12.54 m (41.14 ft.) |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Gearbox | 9 gears, automatic transmission G-TRONIC |
Powertrain & Engine Architecture
The GLS 350d is powered by the OM 656.830, a 3.0-liter inline-six cylinder diesel engine. This engine is a cornerstone of Mercedes-Benz’s modern diesel offerings, known for its refinement and efficiency. It features a steel piston block with aluminum cylinder heads, a variable-geometry turbocharger, and a sophisticated commonrail direct injection system operating at pressures up to 2,700 bar. The engine also incorporates a NANOCOR coating on the cylinder walls to reduce friction. The mild-hybrid system utilizes a 48-volt electrical architecture and integrates a 20 hp electric motor between the engine and the 9G-TRONIC automatic transmission. This system enables features like extended coasting, smoother start/stop operation, and a slight power boost during acceleration. The 9G-TRONIC transmission itself is a nine-speed automatic, offering a wide range of gear ratios for optimized fuel economy and performance.
Driving Characteristics
The GLS 350d delivers a refined and comfortable driving experience. The 650 Nm (479 lb-ft) of torque, available from a low 1350 rpm, provides strong acceleration and effortless overtaking capability. While not as overtly sporty as some of its gasoline-powered siblings, the 350d offers a respectable 0-60 mph time of around 6.4 seconds. The 9G-TRONIC transmission shifts smoothly and efficiently, and the mild-hybrid system contributes to a seamless driving experience. The 4MATIC all-wheel-drive system provides excellent traction in various conditions. The air suspension, standard on the GLS, further enhances ride comfort, absorbing bumps and irregularities in the road surface effectively.
Equipment & Trim Levels
The GLS 350d typically comes well-equipped as standard. Key features include Mercedes-Benz User Experience (MBUX) infotainment system with a large touchscreen display, leather upholstery, heated and ventilated front seats, a panoramic sunroof, and a premium sound system. Standard safety features include adaptive cruise control, lane-keeping assist, automatic emergency braking, and blind-spot monitoring. Optional extras include upgraded leather packages, rear-seat entertainment systems, and various driver-assistance features. The trim level generally sits in the mid-range of the GLS lineup, offering a balance of luxury and value.
Chassis & Braking
The GLS 350d utilizes a sophisticated chassis design featuring an independent multi-link suspension at all four corners, coupled with the AIRMATIC air suspension system. This system allows for adjustable ride height and damping settings, optimizing comfort and handling. The braking system consists of ventilated discs on all wheels, providing ample stopping power. Anti-lock braking system (ABS), electronic stability program (ESP), and brake assist are standard features. The steering is a speed-sensitive power steering system, providing precise and responsive control.
Market Reception & Comparison
The GLS 350d has been generally well-received by automotive critics. It’s praised for its comfortable ride, spacious interior, and fuel efficiency. Compared to the GLS 450 (gasoline), the 350d offers better fuel economy and a more relaxed driving experience, but with slightly less outright performance. Compared to the higher-performance GLS 580, the 350d represents a more sensible and economical choice for buyers who prioritize comfort and practicality over all-out speed. Reliability has been generally good, although diesel engines can be more complex to maintain than gasoline engines.
Legacy
The OM 656 engine family, including the version found in the GLS 350d, is expected to remain a reliable and durable powertrain for years to come. The integration of mild-hybrid technology enhances its efficiency and reduces emissions, making it a more sustainable option. As a used vehicle, the GLS 350d is likely to hold its value well due to its reputation for luxury, comfort, and capability. Regular maintenance, including adherence to Mercedes-Benz’s recommended service intervals, is crucial for ensuring the long-term reliability of this powertrain.
