2002-2005 Mercedes-Benz S-class (W220 facelift ) S 400 CDI V8 (250 Hp) 5G-TRONIC

The Mercedes-Benz S 400 CDI, produced from 2002 to 2005, was a variant of the W220 S-Class facelift model. This model represented a significant offering in the luxury sedan segment, positioned as a high-performance diesel option within the broader S-Class range. The W220 series, launched in 1998, was a technologically advanced vehicle for its time, and the facelift introduced in 2002 refined the design and incorporated updated features. The S 400 CDI specifically catered to buyers seeking the prestige and comfort of an S-Class combined with the efficiency and torque characteristics of a modern diesel engine.

The heart of the S 400 CDI is the OM 628 DE 40 LA/628.960 4.0-liter V8 diesel engine. This engine utilized a sophisticated common rail direct injection system, delivering fuel at extremely high pressure for optimized combustion. The engine featured a bi-turbocharger setup with an intercooler, enhancing both power and torque output. The valvetrain employed four valves per cylinder, contributing to efficient gas exchange. Paired with this engine was the 5G-TRONIC automatic transmission, a five-speed unit known for its smooth shifting and adaptability. This transmission was electronically controlled, offering selectable driving modes to suit different driving conditions and preferences. The engine produced 250 horsepower at 4000 rpm and a substantial 560 Nm (413 lb-ft) of torque between 1700 and 2600 rpm.

In real-world driving, the S 400 CDI offered a compelling blend of performance and refinement. While not as overtly sporty as the gasoline-powered S-Class variants, the diesel V8 provided ample power for effortless cruising and confident overtaking. The 5G-TRONIC transmission was well-matched to the engine’s torque curve, delivering smooth and responsive gear changes. Acceleration from 0 to 60 mph was achieved in approximately 6.7 seconds, and the car had a governed top speed of 154.72 mph (249 km/h). The high torque output meant strong acceleration in everyday driving situations, making it a particularly comfortable vehicle for long distances. Compared to the S320 CDI (a six-cylinder diesel), the S 400 CDI offered significantly more power and a smoother driving experience, while the gasoline-powered S430 and S500 models prioritized outright performance over fuel economy.

The S 400 CDI typically came well-equipped, reflecting its position as a flagship luxury sedan. Standard features included leather upholstery, automatic climate control, power-adjustable seats with memory function, a premium sound system, and a host of safety features such as ABS, traction control, and multiple airbags. Optional extras included features like a navigation system, rear seat entertainment, massaging seats, and various wood and trim options. The interior design was characterized by its elegant and understated aesthetic, emphasizing comfort and sophistication. The dashboard layout was typical of the W220 facelift, with a central display screen controlling various vehicle functions.

The S 400 CDI utilized a robust chassis and braking system designed to handle the vehicle’s weight and performance. The suspension consisted of independent suspension all around, with multi-link setups at both the front and rear. This provided a comfortable ride while maintaining good handling characteristics. Brakes were ventilated discs at the front and solid discs at the rear, with ABS (Anti-lock Braking System) as standard. The steering was a hydraulic power-assisted rack and pinion system, offering precise and responsive control. The car rode on 225/60 R16 tires mounted on 7.5J x 16 inch alloy wheels.

Critics generally praised the S 400 CDI for its refined driving experience, powerful engine, and impressive fuel economy for a vehicle of its size and class. The diesel engine’s torque was a particular highlight, making it a capable and comfortable long-distance cruiser. However, some reviewers noted that the diesel engine was not as quiet or refined as the gasoline alternatives. Fuel economy was rated at approximately 24.5 US mpg combined, a significant advantage over the gasoline-powered S-Class models. Reliability was generally good, although, like all complex vehicles, the S 400 CDI could be subject to age-related issues with components such as the air suspension system and electronic controls.

Today, the S 400 CDI remains a sought-after vehicle among enthusiasts and those seeking a comfortable and capable luxury sedan. The OM 628 engine is known for its durability, and well-maintained examples can still provide reliable service. However, potential buyers should be aware of the potential for age-related issues and the cost of maintaining a complex vehicle like the S-Class. The S 400 CDI represents a unique blend of luxury, performance, and efficiency, making it a compelling option in the used car market.