The Mercedes-Benz S-Class Long (V223) S 350d 9G-TRONIC, produced from 2020 to April 2023, represents a significant iteration of the flagship S-Class sedan. Positioned as a diesel-powered variant within the long-wheelbase V223 generation, it catered to markets prioritizing fuel efficiency and long-distance comfort without sacrificing the luxury and technological advancements synonymous with the S-Class nameplate. The “Long” designation indicates an extended wheelbase, providing increased rear passenger legroom, a feature particularly valued in markets like China and Europe. This model aimed to balance performance with economy, offering a refined driving experience geared towards executive transport and discerning clientele.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | S-class |
| Generation | S-class Long (V223) |
| Type (Engine) | S 350d (286 Hp) 9G-TRONIC |
| Start of production | 2020 |
| End of production | April, 2023 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 4-5 |
| Doors | 4 |
| Combined fuel consumption (WLTP) | 6.4-7.7 l/100 km (36.8 – 30.5 US mpg, 44.1 – 36.7 UK mpg, 15.6 – 13 km/l) |
| CO2 emissions (WLTP) | 169-204 g/km |
| Fuel consumption (economy) – urban (NEDC) | 8.2-8.5 l/100 km (28.7 – 27.7 US mpg, 34.4 – 33.2 UK mpg, 12.2 – 11.8 km/l) |
| Fuel consumption (economy) – extra urban (NEDC) | 5-5.6 l/100 km (47 – 42 US mpg, 56.5 – 50.4 UK mpg, 20 – 17.9 km/l) |
| Fuel consumption (economy) – combined (NEDC) | 6.2-6.7 l/100 km (37.9 – 35.1 US mpg, 45.6 – 42.2 UK mpg, 16.1 – 14.9 km/l) |
| CO2 emissions (NEDC) | 163-176 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 | 250 km/h (155.34 mph), Electronically limited |
| Emission standard | Euro 6D-ISC-FCM |
| Weight-to-power ratio | 6.9 kg/Hp, 145.5 Hp/tonne |
| Weight-to-torque ratio | 3.3 kg/Nm, 305.3 Nm/tonne |
| Power | 286 Hp @ 3400-4600 rpm |
| Power per litre | 97.8 Hp/l |
| Torque | 600 Nm @ 1200-3200 rpm (442.54 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.) |
| Compression ratio | 15.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | BiTurbo, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 9 l (9.51 US qt | 7.92 UK qt) |
| Coolant | 12 l (12.68 US qt | 10.56 UK qt) |
| Kerb Weight | 1965 kg (4332.08 lbs.) |
| Max. weight | 2765 kg (6095.78 lbs.) |
| Max load | 800 kg (1763.7 lbs.) |
| Trunk (boot) space – minimum | 540 l (19.07 cu. ft.) |
| Fuel tank capacity | 65 l (17.17 US gal | 14.3 UK gal) |
| AdBlue tank | 25 l (6.6 US gal | 5.5 UK gal) |
| Max. roof load | 100 kg (220.46 lbs.) |
| Permitted trailer load with brakes (12%) | 2100 kg (4629.71 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Permitted towbar download | 85 kg (187.39 lbs.) |
| Length | 5289 mm (208.23 in.) |
| Width | 1921-1954 mm (75.63 – 76.93 in.) |
| Width including mirrors | 2109 mm (83.03 in.) |
| Height | 1503 mm (59.17 in.) |
| Wheelbase | 3216 mm (126.61 in.) |
| Front track | 1660 mm (65.35 in.) |
| Rear (Back) track | 1688 mm (66.46 in.) |
| Front overhang | 877 mm (34.53 in.) |
| Rear overhang | 1196 mm (47.09 in.) |
| Ride height (ground clearance) | 130 mm (5.12 in.) |
| Drag coefficient (Cd) | 0.22 |
| Minimum turning circle (turning diameter) | 10.8 m (35.43 ft.) |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Number of gears and type of gearbox | 9 gears, automatic transmission G-TRONIC |
Powertrain & Engine Architecture
The S 350d is powered by the OM 656.929, a 2.9-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 utilizes a sophisticated diesel commonrail fuel injection system, delivering fuel at extremely high pressures for optimized combustion. The engine employs a bi-turbocharger setup with an intercooler, enhancing both power and torque across a broad RPM range. The double overhead camshaft (DOHC) valvetrain, with four valves per cylinder, further contributes to the engine’s performance. Paired with the engine is the 9G-TRONIC nine-speed automatic transmission. This transmission is designed for smooth and efficient gear changes, contributing to both fuel economy and driving comfort. The 9G-TRONIC features a wide gear ratio spread, allowing the engine to operate in its optimal efficiency zone more frequently.
Driving Characteristics
The S 350d 9G-TRONIC delivers a driving experience focused on effortless cruising and refined performance. While not as overtly sporty as some of its gasoline-powered siblings, the 600 Nm (442.54 lb-ft) of torque available from 1200-3200 rpm provides ample power for confident overtaking and relaxed highway driving. The nine-speed automatic transmission contributes to a smooth and seamless power delivery. Compared to higher-output S-Class variants, the S 350d prioritizes fuel efficiency and a more relaxed driving style. The gear ratios are tuned for optimal fuel economy, and the engine’s torque curve ensures strong acceleration without requiring frequent downshifts. The long wheelbase and air suspension contribute to a comfortable and composed ride, even on less-than-perfect road surfaces.
Equipment & Trim Levels
The S 350d Long typically came standard with a high level of equipment, befitting its flagship status. Standard features included leather upholstery, heated and ventilated front seats with massage functions, a Burmester surround sound system, and the latest generation of Mercedes-Benz’s MBUX infotainment system with a large touchscreen display. Optional extras included rear-seat entertainment systems, premium leather packages, and a variety of driver-assistance features such as adaptive cruise control, lane-keeping assist, and automatic parking. Interior trim options ranged from wood veneers to aluminum accents, allowing buyers to personalize the cabin to their preferences.
Chassis & Braking
The V223 S-Class features an independent multi-link suspension at both the front and rear, coupled with an air suspension system. This combination provides a remarkably comfortable ride and excellent handling characteristics. The air suspension allows for adjustable ride height and damping settings, further enhancing comfort and control. Braking duties are handled by ventilated discs on all four wheels, providing ample stopping power. Anti-lock braking system (ABS) is standard, along with electronic stability control. Many models were also equipped with 4-wheel steering, enhancing maneuverability at low speeds and stability at high speeds.
Market Reception & Comparison
The S 350d Long was generally well-received by automotive critics, who praised its refined engine, comfortable ride, and luxurious interior. It was often seen as a sensible choice for buyers prioritizing fuel efficiency and long-distance comfort. Compared to the S 450 or S 580 models, the S 350d offered comparable levels of luxury and technology at a lower price point, albeit with slightly less outright performance. Its fuel economy was significantly better than the gasoline-powered variants, making it an attractive option for those covering high mileage. Reliability reports have generally been positive, with the OM 656 engine proving to be a robust and durable unit.
Legacy
The Mercedes-Benz S-Class Long (V223) S 350d 9G-TRONIC represents a compelling blend of luxury, technology, and efficiency. The OM 656 diesel engine has established itself as a reliable and refined powerplant, and the 9G-TRONIC transmission contributes to a smooth and comfortable driving experience. On the used car market, these models are sought after for their combination of features and value. The long wheelbase and luxurious interior continue to appeal to buyers seeking a premium and comfortable sedan. The S 350d’s focus on fuel efficiency also makes it an attractive option in a market increasingly concerned with environmental impact.
