2017-2020 Mercedes-Benz S-class Long (V222 facelift ) S 400d (340 Hp) 4MATIC G-TRONIC

The Mercedes-Benz S 400d 4MATIC, part of the V222 S-Class Long wheelbase facelift introduced in 2017, represented a significant offering in the luxury sedan segment. Produced through 2020, this variant combined a powerful diesel engine with all-wheel drive and a sophisticated automatic transmission, aiming to deliver both performance and efficiency. Positioned as a mid-to-upper tier trim within the S-Class range, it slotted between the entry-level S 350d and the higher-performance S 560 models. The “Long” designation indicates an extended wheelbase, prioritizing rear passenger space – a key feature for markets where chauffeur-driven travel is common.

Technical Specifications

INTRODUCTION

The S 400d 4MATIC, launched as part of the V222 S-Class facelift in 2017, represented Mercedes-Benz’s commitment to blending luxury with diesel efficiency. The V222 generation, produced from 2013 to 2020, received a substantial refresh in 2017, incorporating updated styling, enhanced technology, and new powertrain options. The S 400d, powered by the new OM 656 engine, was a key component of this update, offering a compelling alternative to gasoline-powered S-Class models, particularly in European markets where diesel fuel was prevalent and subject to favorable taxation. The “Long” wheelbase version, with its extended rear passenger compartment, catered to buyers prioritizing comfort and prestige.

Powertrain & Engine Architecture

At the heart of the S 400d lies the OM 656 2.9-liter inline-six cylinder diesel engine. This engine marked a departure from the previous V6 diesel configurations used in the S-Class, offering improved refinement and efficiency. The OM 656 utilizes a sophisticated diesel commonrail fuel injection system, capable of delivering multiple injections per combustion cycle for optimized fuel burn and reduced emissions. A variable geometry turbocharger with water intercooling further enhances performance and responsiveness. The engine boasts a high compression ratio of 15.5:1, contributing to its thermal efficiency. Paired with the engine is the 9G-TRONIC nine-speed automatic transmission. This transmission is known for its smooth shifts and wide gear ratio spread, optimizing both fuel economy and acceleration. The 4MATIC all-wheel-drive system distributes power between the front and rear axles, providing enhanced traction and stability in various driving conditions.

Driving Characteristics

The S 400d 4MATIC delivers a refined and effortless driving experience. The 700 Nm (516 lb-ft) of torque, available from a low 1200 rpm, provides strong acceleration in virtually any gear. The 0-60 mph sprint takes approximately 4.9 seconds, making it a surprisingly quick luxury sedan. The 9G-TRONIC transmission contributes to this performance, seamlessly selecting the optimal gear for any given situation. Compared to the S 350d, the S 400d offers a noticeable performance increase, while remaining more fuel-efficient than the gasoline-powered S 560. The long wheelbase contributes to a comfortable ride, absorbing bumps and imperfections in the road with ease. The 4MATIC system provides confident handling, particularly in inclement weather.

Equipment & Trim Levels

The S 400d 4MATIC Long typically came well-equipped as standard. Features included leather upholstery, heated and ventilated front seats with massage functions, a premium Burmester sound system, and a large infotainment screen with Mercedes’ COMAND system. Standard safety features included adaptive cruise control, lane keeping assist, and automatic emergency braking. Optional extras included rear seat entertainment systems, a panoramic sunroof, and various interior trim options. The interior design emphasized luxury and sophistication, with high-quality materials and meticulous attention to detail. Dashboard configurations were generally consistent across the V222 facelift models, with minor variations depending on optional equipment.

Chassis & Braking

The S 400d 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. Air suspension was often included as standard or an option, further enhancing ride quality and allowing for adjustable ride height. The braking system consists of ventilated discs on all four wheels, providing ample stopping power. Anti-lock braking system (ABS), electronic stability control (ESC), and brake assist are standard safety features. The steering system is a rack-and-pinion type with electric power steering, offering precise and responsive steering feel.

Market Reception & Comparison

The S 400d 4MATIC was generally well-received by automotive critics. It was praised for its powerful and efficient engine, comfortable ride, and luxurious interior. Compared to the S 350d, the S 400d offered a significant performance upgrade without a substantial penalty in fuel economy. Against the S 560, the S 400d provided a more economical option with comparable levels of luxury and refinement. However, some critics noted that the diesel engine, while refined, lacked the smoothness and responsiveness of the gasoline-powered alternatives. Fuel economy figures were competitive for the segment, with combined fuel consumption ranging from 5.6 to 5.7 liters per 100 kilometers.

Legacy

The OM 656 engine, introduced with the S 400d, has proven to be a reliable and durable powertrain. While long-term reliability data is still accumulating, early indications suggest that the engine is robust and capable of high mileage. In the used car market, the S 400d 4MATIC Long remains a desirable option for buyers seeking a luxurious and efficient grand tourer. Its combination of performance, comfort, and technology continues to appeal to discerning buyers. The V222 S-Class, as a whole, is considered a landmark vehicle in the luxury sedan segment, and the S 400d 4MATIC represents a particularly well-rounded and appealing variant.