The Mercedes-Benz S 350d Long, produced from 2017 to 2020 as part of the V222 facelift generation of the S-Class, represented a compelling blend of luxury, performance, and efficiency. Positioned as a mid-range offering within the long-wheelbase S-Class lineup, it catered to buyers seeking a sophisticated executive sedan with strong diesel power and the advanced technology for which the S-Class is renowned. This variant aimed to provide a comfortable and refined driving experience, particularly suited for long-distance travel, while maintaining competitive fuel economy. The “Long” designation indicates an extended wheelbase, offering significantly increased rear passenger legroom compared to the standard-wheelbase S-Class.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | S-class |
| Generation | S-class Long (V222, facelift 2017) |
| Type (Engine) | S 350d (286 Hp) G-TRONIC |
| Start of production | 2017 |
| End of production | 2020 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 4 |
| Doors | 4 |
| Fuel consumption at Low speed (WLTP) | 6.4 l/100 km (36.8 US mpg, 44.1 UK mpg, 15.6 km/l) |
| Fuel consumption at very high speed (WLTP) | 7.3 l/100 km (32.2 US mpg, 38.7 UK mpg, 13.7 km/l) |
| CO2 emissions (WLTP) | 168-190 g/km |
| Fuel consumption (economy) – urban | 6.4-6.5 l/100 km (36.8 – 36.2 US mpg, 44.1 – 43.5 UK mpg, 15.6 – 15.4 km/l) |
| Fuel consumption (economy) – extra urban | 4.4-4.7 l/100 km (53.5 – 50 US mpg, 64.2 – 60.1 UK mpg, 22.7 – 21.3 km/l) |
| Fuel consumption (economy) – combined | 5.1-5.4 l/100 km (46.1 – 43.6 US mpg, 55.4 – 52.3 UK mpg, 19.6 – 18.5 km/l) |
| CO2 emissions | 134-139 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 6 sec |
| Acceleration 0 – 62 mph | 6 sec |
| Acceleration 0 – 60 mph | 5.7 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 6.7 kg/Hp, 149.3 Hp/tonne |
| Weight-to-torque ratio | 3.2 kg/Nm, 313.3 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 |
| Compression ratio | 15.5:1 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Engine oil capacity | 8.5 l (8.98 US qt | 7.48 UK qt) |
| Coolant | 13 l (13.74 US qt | 11.44 UK qt) |
| Kerb Weight | 1915 kg (4221.85 lbs.) |
| Max. weight | 2720 kg (5996.57 lbs.) |
| Max load | 805 kg (1774.72 lbs.) |
| Trunk (boot) space – minimum | 510 l (18.01 cu. ft.) |
| Fuel tank capacity | 70 l (18.49 US gal | 15.4 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.) |
| Length | 5271 mm (207.52 in.) |
| Width | 1905 mm (75 in.) |
| Width including mirrors | 2130 mm (83.86 in.) |
| Height | 1496 mm (58.9 in.) |
| Wheelbase | 3165 mm (124.61 in.) |
| Front track | 1630 mm (64.17 in.) |
| Rear (Back) track | 1643 mm (64.69 in.) |
| Front overhang | 898 mm (35.35 in.) |
| Rear overhang | 1208 mm (47.56 in.) |
| Drag coefficient (Cd) | 0.24 |
| Minimum turning circle (turning diameter) | 12.3 m (40.35 ft.) |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels of the vehicle. |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 9 gears, automatic transmission G-TRONIC |
| Front suspension | Independent multi-link suspension |
| Rear suspension | Independent multi-link 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 | 245/55 R17 |
| Wheel rims size | 17 |
INTRODUCTION
The Mercedes-Benz S 350d Long (V222 facelift) debuted in 2017, building upon the already highly regarded V222 S-Class. The facelift brought revised styling, updated technology, and refined engine options. This particular variant, the S 350d Long, was a key offering in many European and Asian markets, where diesel engines remained popular due to their fuel efficiency and torque characteristics. In the US market, where diesel passenger cars were less common, the S-Class range primarily consisted of gasoline-powered models. The S 350d Long aimed to deliver the flagship S-Class experience – unparalleled comfort, advanced safety features, and a prestigious image – with the added benefit of lower running costs compared to its gasoline counterparts.
Powertrain & Engine Architecture
At the heart of the S 350d Long lies the OM 656.929, a 2.9-liter inline-six cylinder diesel engine. This engine represented a significant advancement in Mercedes-Benz diesel technology, featuring a sophisticated commonrail direct injection system operating at pressures up to 2,700 bar. This high-pressure injection, combined with a variable geometry turbocharger and intercooler, allowed for exceptional fuel atomization and efficient combustion. The engine produced 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. The engine also incorporated a diesel particulate filter (DPF) to meet stringent Euro 6 emissions standards. Paired with the engine was the 9G-TRONIC nine-speed automatic transmission. This transmission offered smooth and efficient gear changes, contributing to both fuel economy and driving comfort. The transmission’s wide gear ratio spread allowed the engine to operate within its optimal torque band more frequently.
Driving Characteristics
The S 350d Long, with its 286 hp and 600 Nm of torque, provided a relaxed and effortless driving experience. While not as overtly sporty as some of the higher-powered S-Class variants (like the S 500), it offered ample acceleration for everyday driving and highway cruising. The 0-60 mph sprint took approximately 5.7 seconds, and the car was electronically limited to a top speed of 155 mph. The 9G-TRONIC transmission played a crucial role in delivering smooth power delivery, and the close gear ratios ensured that the engine was always in its sweet spot. Compared to the gasoline-powered S 400 or S 500, the S 350d Long prioritized torque over outright horsepower, resulting in stronger low-end and mid-range acceleration. This made it particularly well-suited for overtaking maneuvers and driving in hilly terrain. The long wheelbase contributed to a comfortable and stable ride, absorbing bumps and imperfections in the road with ease.
Equipment & Trim Levels
The S 350d Long 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, a premium sound system, multi-contour seats with massage function, and a panoramic sunroof. Safety features were also abundant, including adaptive cruise control, lane keeping assist, automatic emergency braking, and a 360-degree camera system. Optional extras included upgraded leather packages, rear-seat entertainment systems, and various driver assistance technologies. The “Long” designation meant that rear passengers benefited from significantly increased legroom, making it a popular choice for chauffeur-driven executives.
Chassis & Braking
The S 350d Long featured an advanced chassis design focused on ride comfort and handling. It utilized an independent multi-link suspension system at both the front and rear axles, providing a smooth and controlled ride. Air suspension was standard, allowing the ride height to be adjusted for optimal comfort or ground clearance. Braking duties were handled by ventilated disc brakes on all four wheels, providing ample stopping power. Anti-lock braking system (ABS), electronic stability control (ESC), and traction control were standard safety features. The steering system was a rack-and-pinion setup with electric power assistance, offering precise and responsive steering feel.
Market Reception & Comparison
The S 350d Long was generally well-received by automotive critics. It was praised for its refined driving experience, luxurious interior, and impressive fuel economy. Compared to the gasoline-powered S-Class models, the S 350d Long offered a more affordable entry point into the flagship sedan range while still delivering a high level of luxury and performance. Against competitors like the BMW 7 Series and Audi A8, the S 350d Long held its own, offering a compelling combination of comfort, technology, and efficiency. Some critics noted that the diesel engine, while powerful, lacked the outright refinement of the gasoline engines, but the fuel economy benefits were often considered a worthwhile trade-off.
Legacy
The OM 656 engine family, including the one found in the S 350d Long, has proven to be remarkably reliable. While diesel engines generally require diligent maintenance, these engines are known for their durability and longevity. On the used car market, the S 350d Long remains a desirable option for buyers seeking a luxurious and efficient executive sedan. Its combination of comfort, technology, and fuel economy continues to appeal to a wide range of buyers. The V222 S-Class, as a whole, is considered a landmark vehicle in the luxury sedan segment, and the S 350d Long represents a particularly well-rounded and practical variant within the range.
