The Mercedes-Benz GLS 350d 4MATIC G-TRONIC, produced from October 2019 to September 2023, represents a key variant within the X167 generation of the GLS full-size luxury SUV. Positioned as a diesel-powered option within the lineup, it offered a balance between performance, fuel efficiency, and capability for buyers seeking a spacious, seven-passenger vehicle. The X167 GLS marked the third generation of Mercedes-Benz’s flagship SUV, succeeding the X166, and aimed to provide a more refined and technologically advanced experience compared to its predecessor. This particular 350d trim served as a popular choice for those prioritizing torque and long-distance comfort over outright speed, particularly in European markets where diesel engines remained prevalent.
| Brand | Mercedes-Benz |
| Model | GLS |
| Generation | GLS (X167) |
| Type | GLS 350d (286 Hp) 4MATIC G-TRONIC |
| Start of production | October, 2019 |
| End of production | September, 2023 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | SUV |
| Seats | 7 |
| Doors | 5 |
| Fuel consumption (urban) | 8.6-10 l/100 km (27.4 – 23.5 US mpg) |
| Fuel consumption (extra urban) | 6.1-6.9 l/100 km (38.6 – 34.1 US mpg) |
| Fuel consumption (combined) | 7.1-8.1 l/100 km (33.1 – 29 US mpg) |
| CO2 emissions | 187-121 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 7 sec |
| Acceleration 0 – 62 mph | 7 sec |
| Acceleration 0 – 60 mph | 6.7 sec |
| Maximum speed | 227 km/h (141.05 mph) |
| Emission standard | Euro 6d ISC-FCM |
| Weight-to-power ratio | 8.5 kg/Hp |
| Weight-to-torque ratio | 4 kg/Nm |
| Power | 286 Hp @ 3400-4600 rpm |
| Torque | 600 Nm @ 1200-3200 rpm (442.54 lb.-ft.) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | OM 656 D 29 R SCR |
| Engine displacement | 2925 cm3 (178.49 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | BiTurbo, Intercooler |
| Engine oil capacity | 8.5 l (8.98 US qt | 7.48 UK qt) |
| Kerb Weight | 2425 kg (5346.21 lbs.) |
| Max. weight | 3250 kg (7165.02 lbs.) |
| Max load | 825 kg (1818.81 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) |
| Permitted trailer load with brakes (12%) | 3500 kg (7716.18 lbs.) |
| Length | 5207 mm (205 in.) |
| Width | 1956 mm (77.01 in.) |
| Width including mirrors | 2030 mm (79.92 in.) |
| Height | 1823-1838 mm (71.77 – 72.36 in.) |
| Wheelbase | 3135 mm (123.43 in.) |
| Front track | 1669 mm (65.71 in.) |
| Rear track | 1692 mm (66.61 in.) |
| Front overhang | 936 mm (36.85 in.) |
| Rear overhang | 1136 mm (44.72 in.) |
| Ride height (ground clearance) | 200-215 mm (7.87 – 8.46 in.) |
| Drivetrain Architecture | All wheel drive (4×4) |
| Number of gears | 9 |
| Gearbox type | automatic transmission G-TRONIC |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Front tires | 275/45 R21 |
| Rear tires | 315/40 R21 |
Powertrain & Engine Architecture
The GLS 350d is powered by the OM 656 D 29 R SCR, a 2.9-liter inline-six diesel engine. This engine represents a significant advancement over previous Mercedes-Benz diesel engines, featuring a lightweight aluminum construction, a stepped combustion process, and a two-stage turbocharging system. The two turbochargers work in sequence, with a smaller turbo providing boost at low engine speeds for improved responsiveness, and a larger turbo taking over at higher speeds for increased power. The engine utilizes a common-rail direct injection system with piezo injectors, delivering fuel at extremely high pressures for optimized combustion. The SCR (Selective Catalytic Reduction) system is integral to meeting stringent emissions standards, utilizing AdBlue to reduce nitrogen oxide (NOx) emissions. Paired with the engine is the 9G-TRONIC nine-speed automatic transmission, known for its smooth shifting and wide gear ratio spread. This transmission is designed to optimize fuel efficiency and provide comfortable cruising at highway speeds. The 4MATIC all-wheel-drive system distributes power between the front and rear axles, enhancing traction and stability in various driving conditions.
Driving Characteristics
The GLS 350d 4MATIC G-TRONIC delivers a refined and comfortable driving experience. The engine’s substantial 600 Nm (442.54 lb-ft) of torque, available from a low 1200 rpm, provides effortless acceleration and strong pulling power, making it well-suited for towing and carrying a full load of passengers. While not as overtly sporty as some of the higher-performance GLS variants, the 350d offers a respectable 0-60 mph time of around 6.7 seconds. The 9G-TRONIC transmission contributes to smooth gear changes and helps keep the engine operating within its optimal efficiency range. The all-wheel-drive system provides confident handling in all weather conditions. Compared to the GLS 450 (gasoline) or the AMG-tuned variants, the 350d prioritizes fuel economy and relaxed cruising over outright performance. The manual transmission was not offered on this variant in the US market.
Equipment & Trim Levels
The GLS 350d 4MATIC G-TRONIC came standard with a comprehensive array of luxury features. Interior appointments typically included leather upholstery, power-adjustable front seats with memory function, and a premium sound system. Standard technology features included the Mercedes-Benz User Experience (MBUX) infotainment system with a large touchscreen display, navigation, Apple CarPlay and Android Auto integration, and a suite of driver-assistance systems such as adaptive cruise control, lane-keeping assist, and automatic emergency braking. Optional extras included air suspension, massaging seats, a panoramic sunroof, and upgraded interior trim materials. Trim levels beyond the base 350d often included packages that bundled popular options together, such as the Premium Package or the AMG Line Package, which added sporty styling cues.
Chassis & Braking
The GLS 350d features a sophisticated chassis designed to provide a comfortable ride and stable handling. It utilizes an independent suspension system with air suspension available as an option, allowing for adjustable ride height and damping. The air suspension enhances ride comfort and provides increased ground clearance for off-road driving. The braking system consists of ventilated discs on all four wheels, providing ample stopping power. Anti-lock braking system (ABS), electronic stability control (ESC), and brake assist are standard features. The GLS 350d’s suspension tuning is geared towards comfort and stability, prioritizing a smooth ride over aggressive handling. Stabilizer bars are fitted front and rear to reduce body roll during cornering.
Market Reception & Comparison
The GLS 350d 4MATIC G-TRONIC was generally well-received by automotive critics. It was praised for its spacious interior, comfortable ride, and fuel-efficient diesel engine. Critics noted that the diesel engine provided ample torque for effortless cruising and towing. Compared to the gasoline-powered GLS 450, the 350d offered significantly better fuel economy, making it a more practical choice for long-distance drivers. However, some critics found the diesel engine to be less refined than the gasoline engine, with slightly more noticeable engine noise and vibration. In terms of reliability, the OM 656 engine has proven to be generally robust, although diesel engines can be more susceptible to issues related to the emissions control system.
Legacy
The Mercedes-Benz GLS 350d 4MATIC G-TRONIC represents a compelling option in the luxury SUV segment, particularly for buyers seeking a diesel-powered vehicle. The OM 656 engine has established itself as a reliable and efficient powerplant, and the 9G-TRONIC transmission contributes to a smooth and comfortable driving experience. On the used car market, these models hold their value reasonably well, reflecting the enduring appeal of the GLS platform and the desirability of the diesel engine in certain regions. While newer GLS models offer even more advanced technology and features, the X167 350d remains a capable and luxurious SUV that provides a refined and practical driving experience.
