The Mercedes-Benz S 350d 4MATIC, produced from 2017 to 2020 as part of the W222 facelift generation of the S-Class, represented a compelling blend of luxury, performance, and efficiency. Positioned as a mid-range offering within the S-Class lineup, it served as a more economical alternative to the petrol-powered S 500 and S 600 models, while offering a significant step up in refinement and features compared to the entry-level S 300 variants. This model aimed to appeal to buyers prioritizing long-distance comfort and fuel economy without sacrificing the prestige associated with the S-Class nameplate. The W222 facelift, introduced in 2017, brought revised styling, updated technology, and enhanced engine options, solidifying the S-Class’s position as a benchmark in the luxury sedan segment.
Powertrain & Engine Architecture
The heart of the S 350d 4MATIC is the OM 656.929, a 2.9-liter inline-six cylinder diesel engine. This engine marked a significant departure from the previous V6 diesel offerings, representing a new generation of Mercedes-Benz diesel technology. It boasts a sophisticated diesel commonrail fuel injection system operating at extremely high pressures (2,700 bar) for optimized combustion and reduced emissions. The engine utilizes a single-stage turbocharger with variable geometry turbine (VGT) technology and an intercooler to maximize power and torque across a broad RPM range. A key feature of the OM 656 is its steel piston design, a move away from aluminum pistons used in previous generations, enhancing durability and allowing for higher cylinder pressures. The compression ratio is a high 15.5:1, contributing to thermal efficiency.
The “G-TRONIC” 9-speed automatic transmission (9G-TRONIC) is paired with the engine. This transmission is known for its smooth and quick shifts, contributing to both performance and fuel economy. The gear ratios are carefully tuned to provide strong acceleration in lower gears and relaxed cruising at highway speeds. The transmission features a torque converter lockup clutch that engages early to minimize slippage and improve efficiency. The 9G-TRONIC also incorporates adaptive shift programs that learn the driver’s style and adjust shift points accordingly.
Engine Specifications
The OM 656.929 engine produces 286 horsepower at 3,400-4,600 rpm and a substantial 600 Nm (442.54 lb-ft) of torque between 1,200-3,200 rpm. This broad torque curve provides effortless acceleration and strong pulling power, making it well-suited for long-distance highway driving and overtaking maneuvers. The engine’s power-to-liter ratio is an impressive 97.8 hp/liter.
Driving Characteristics
The S 350d 4MATIC delivers a refined and comfortable driving experience. The abundant torque from the diesel engine provides strong off-the-line acceleration and effortless cruising. While not as overtly sporty as the higher-powered S-Class models, the S 350d offers more than adequate performance for most drivers. The 0-62 mph (0-100 km/h) acceleration time of 5.8 seconds is respectable for a large luxury sedan. The 9G-TRONIC transmission contributes to smooth and seamless gear changes, minimizing disruptions to the driving experience. The 4MATIC all-wheel-drive system provides enhanced traction and stability, particularly in adverse weather conditions. Compared to the petrol-powered S 500, the S 350d offers a more relaxed and fuel-efficient driving experience, while the S 300 provides less power and refinement.
Equipment & Trim Levels
The S 350d 4MATIC came standard with a comprehensive array of luxury features. Interior appointments typically included high-quality leather upholstery, wood trim, and brushed aluminum accents. Standard equipment included Mercedes-Benz’s COMAND infotainment system with a large central display screen, navigation, Bluetooth connectivity, and a premium sound system. Driver assistance features such as adaptive cruise control, lane keeping assist, and automatic emergency braking were also commonly included. Optional extras included features such as a panoramic sunroof, massaging seats, a rear-seat entertainment system, and upgraded leather upholstery. The S 350d 4MATIC was generally offered with a relatively limited number of trim packages, focusing on enhancing existing features rather than drastically altering the vehicle’s overall character.
Chassis & Braking
The S 350d 4MATIC utilizes an independent multi-link suspension system at both the front and rear axles. This suspension design provides a comfortable ride and precise handling. The suspension is electronically controlled, allowing for adjustments to damping rates based on road conditions and driving style. The S-Class features ventilated disc brakes at all four corners, providing ample stopping power. Anti-lock braking system (ABS), electronic stability control (ESC), and traction control are standard safety features. The steering system is a rack-and-pinion type with electric power steering, offering precise and responsive steering feel. The standard tire size is 245/55 R17, mounted on 17-inch alloy wheels.
Market Reception & Comparison
The S 350d 4MATIC was generally well-received by automotive critics. It was praised for its refined ride, powerful and efficient engine, and luxurious interior. Critics noted that the diesel engine provided ample power and torque for comfortable highway cruising, while also delivering excellent fuel economy. Fuel consumption figures ranged from 5.5-5.7 l/100 km (42.8-41.3 US mpg) combined, making it a more economical choice than the petrol-powered S-Class models. Compared to the S 500, the S 350d offered a more balanced combination of performance and efficiency. Reliability reports suggest that the OM 656 engine has proven to be a robust and durable unit, although diesel engines generally require more diligent maintenance than their petrol counterparts.
Technical Specifications
| Body type | Sedan, 4 Doors, 4-5 Seats |
| Fuel economy (combined) | 5.5-5.7 l/100 km (42.8 – 41.3 US mpg) |
| CO2 emissions | 181-205 g/km |
| Acceleration 0-100 km/h | 5.8 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Engine displacement | 2925 cm3 (178.49 cu. in.) |
| Number of cylinders | 6 (Inline) |
| Power | 286 Hp @ 3400-4600 rpm |
| Torque | 600 Nm @ 1200-3200 rpm (442.54 lb.-ft.) |
| Engine Model/Code | OM 656.929 |
| Kerb Weight | 1950 kg (4299.01 lbs.) |
| Max. weight | 2740 kg (6040.67 lbs.) |
| Trunk (boot) space | 510 l (18.01 cu. ft.) |
| Fuel tank capacity | 70 l (18.49 US gal) |
| Gearbox | 9 gears, automatic transmission G-TRONIC |
| Drive wheel | All wheel drive (4×4) |
| Length | 5141 mm (202.4 in.) |
| Width | 1905 mm (75 in.) |
| Height | 1498 mm (58.98 in.) |
Legacy
The Mercedes-Benz S 350d 4MATIC (W222 facelift) has established itself as a desirable used car option. The OM 656 engine has proven to be relatively reliable, and the S-Class’s reputation for luxury and comfort continues to attract buyers. However, potential buyers should be aware of the higher maintenance costs associated with diesel engines, including the potential for issues with the diesel particulate filter (DPF) and the AdBlue system. Despite these considerations, the S 350d 4MATIC remains a compelling choice for those seeking a luxurious and efficient long-distance cruiser. Its blend of performance, comfort, and technology ensures its continued relevance in the used car market for years to come.
