The Mercedes-Benz S 450 CDI Long, produced from 2009 to 2010, represented a compelling blend of luxury, performance, and efficiency within the V221 S-Class facelift range. Positioned as a high-end diesel variant of the long-wheelbase S-Class, it catered to buyers seeking a refined grand touring experience with reduced running costs compared to its gasoline counterparts. This model was primarily aimed at the European market, where diesel engines held significant popularity due to favorable taxation and fuel economy. The “Long” designation indicated an extended wheelbase, providing increased rear passenger legroom – a key feature for chauffeur-driven executives and discerning customers prioritizing rear seat comfort.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | S-class |
| Generation | S-class Long (V221, facelift 2009) |
| Type (Engine) | S 450 CDI V8 (320 Hp) G-TRONIC |
| Start of production | 2009 |
| End of production | 2010 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 13-13.2 l/100 km (18.1 – 17.8 US mpg, 21.7 – 21.4 UK mpg, 7.7 – 7.6 km/l) |
| Fuel consumption (extra urban) | 6.9-7.1 l/100 km (34.1 – 33.1 US mpg, 40.9 – 39.8 UK mpg, 14.5 – 14.1 km/l) |
| Fuel consumption (combined) | 9.1-9.3 l/100 km (25.8 – 25.3 US mpg, 31 – 30.4 UK mpg, 11 – 10.8 km/l) |
| CO2 emissions | 240-245 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 6.6 sec |
| Acceleration 0 – 62 mph | 6.6 sec |
| Acceleration 0 – 60 mph | 6.3 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Weight-to-power ratio | 6.5 kg/Hp, 154.2 Hp/tonne |
| Weight-to-torque ratio | 2.8 kg/Nm, 351.8 Nm/tonne |
| Power | 320 Hp @ 3600 rpm |
| Power per litre | 80.1 Hp/l |
| Torque | 730 Nm @ 2200 rpm (538.42 lb.-ft. @ 2200 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | OM 629.911 |
| Engine displacement | 3996 cm3 (243.85 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Compression ratio | 17:1 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Engine oil capacity | 10.5 l (11.1 US qt | 9.24 UK qt) |
| Coolant | 10.5 l (11.1 US qt | 9.24 UK qt) |
| Kerb Weight | 2075 kg (4574.59 lbs.) |
| Max. weight | 2700 kg (5952.48 lbs.) |
| Max load | 625 kg (1377.89 lbs.) |
| Trunk (boot) space – minimum | 560 l (19.78 cu. ft.) |
| Fuel tank capacity | 90 l (23.78 US gal | 19.8 UK gal) |
| Length | 5226 mm (205.75 in.) |
| Width | 1871 mm (73.66 in.) |
| Width including mirrors | 2120 mm (83.46 in.) |
| Height | 1479 mm (58.23 in.) |
| Wheelbase | 3165 mm (124.61 in.) |
| Front track | 1600 mm (62.99 in.) |
| Rear (Back) track | 1606 mm (63.23 in.) |
| Front overhang | 888 mm (34.96 in.) |
| Rear overhang | 1173 mm (46.18 in.) |
| Minimum turning circle | 12.2 m (40.03 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 7 gears, automatic transmission G-TRONIC |
| Front brakes | Disc |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Tires size | 255/45 R18 |
| Wheel rims size | 18 |
INTRODUCTION
The S 450 CDI Long, introduced as part of the V221 facelift in 2009, offered a compelling alternative to the gasoline-powered S-Class models. The V221 generation, produced from 2005 to 2013, represented a significant leap forward in Mercedes-Benz luxury and technology. The facelift brought revised styling, updated interior features, and improved engine options, including the refined OM 629.911 V8 diesel. The CDI variant specifically targeted buyers who desired the prestige and comfort of the S-Class but prioritized fuel efficiency and torque delivery for long-distance cruising. It occupied a position between the entry-level S 350 and the more performance-oriented S 500 models in the lineup.
Powertrain & Engine Architecture
At the heart of the S 450 CDI Long lies the OM 629.911 4.0-liter V8 diesel engine. This engine is a sophisticated design featuring a common rail direct injection system, a variable geometry turbocharger, and an intercooler. The common rail system, operating at extremely high pressures, ensures precise fuel delivery and optimized combustion. The V8 configuration provides inherent smoothness and refinement, while the turbocharger boosts power and torque significantly. The engine produces 320 horsepower at 3600 rpm and a substantial 730 Nm (538 lb-ft) of torque at just 2200 rpm. This torque peak, available at relatively low engine speeds, contributes to effortless acceleration and strong in-gear performance. The engine is paired with Mercedes-Benz’s 7G-TRONIC seven-speed automatic transmission. This transmission is known for its smooth and responsive shifts, contributing to a comfortable driving experience. The 7G-TRONIC features a torque converter lock-up clutch that engages at higher speeds to improve fuel efficiency.
Driving Characteristics
The S 450 CDI Long delivers a driving experience characterized by effortless power and refined comfort. The high torque output of the diesel engine allows for brisk acceleration, with 0-60 mph achieved in approximately 6.3 seconds. While not as overtly sporty as the gasoline-powered S 500, the S 450 CDI offers ample performance for overtaking and highway cruising. The 7G-TRONIC transmission is well-matched to the engine, providing smooth and seamless gear changes. The long wheelbase contributes to a stable and comfortable ride, absorbing bumps and imperfections in the road surface effectively. Compared to the S 350, the S 450 CDI offers significantly more power and torque, resulting in a more relaxed and confident driving experience. Compared to the S 500, the S 450 CDI prioritizes fuel efficiency and torque delivery over outright horsepower, making it a better choice for long-distance journeys.
Equipment & Trim Levels
The S 450 CDI Long came generously equipped as standard, reflecting its position as a flagship luxury sedan. Standard features typically included leather upholstery, wood trim, a premium sound system, automatic climate control, power-adjustable seats with memory function, and a comprehensive suite of safety features, including ABS, ESP, and multiple airbags. The long wheelbase provided increased rear passenger legroom, often accompanied by features such as reclining rear seats, a rear entertainment system, and individual climate control for rear passengers. Optional extras included a panoramic sunroof, advanced driver-assistance systems (such as Distronic adaptive cruise control and lane-keeping assist), and upgraded interior trim options.
Chassis & Braking
The S 450 CDI Long utilizes a sophisticated chassis design focused on ride comfort and handling stability. It features an independent suspension system with multi-link front and rear axles. The suspension is tuned to provide a smooth and controlled ride, even on uneven surfaces. The braking system consists of ventilated disc brakes on all four wheels, coupled with ABS (Anti-lock Braking System) and ESP (Electronic Stability Program) for enhanced safety. The S-Class also featured Mercedes-Benz’s Brake Assist system, which automatically applies maximum braking force in emergency situations.
Market Reception & Comparison
The S 450 CDI Long was generally well-received by automotive critics, who praised its blend of luxury, performance, and fuel efficiency. Reviewers noted the engine’s smooth power delivery and impressive torque, as well as the comfortable ride quality and spacious interior. Fuel economy was a significant selling point, with the S 450 CDI achieving combined fuel consumption figures of around 9.1-9.3 l/100 km (25.8-25.3 US mpg). Compared to the S 500, the S 450 CDI offered comparable performance with significantly lower running costs. However, some critics noted that the diesel engine was not as refined or responsive as the gasoline-powered alternatives.
Legacy
The OM 629.911 engine, while no longer in production, is known for its durability and reliability. Properly maintained examples of the S 450 CDI Long can still provide years of reliable service. In the used car market, these models are sought after by buyers who appreciate the combination of luxury, performance, and fuel efficiency. However, potential buyers should be aware of the higher maintenance costs associated with diesel engines, particularly regarding the diesel particulate filter (DPF) and fuel injection system. The S 450 CDI Long represents a significant chapter in the S-Class’s history, showcasing Mercedes-Benz’s commitment to innovation and refinement.
