2020-2023 Mercedes-Benz S-class (W223) S 450 (367 Hp) EQ Boost 4MATIC 9G-TRONIC

The Mercedes-Benz S-Class (W223) S 450 4MATIC, produced from 2020 through April 2023, represents a significant iteration of the flagship luxury sedan. This variant, equipped with a 3.0-liter inline-six engine featuring EQ Boost mild-hybrid technology and a 9G-TRONIC automatic transmission, occupied a crucial mid-range position within the W223 lineup, bridging the gap between the entry-level S 350 (where offered) and the higher-performance S 580 models. The S 450 4MATIC aimed to deliver a refined balance of power, efficiency, and advanced technology, appealing to buyers prioritizing a comfortable and sophisticated driving experience.

Powertrain & Engine Architecture

At the heart of the S 450 4MATIC lies the M 256.930 engine, a 2,999 cc (183.01 cu. in.) inline-six cylinder gasoline engine. This engine is notable for its innovative features, including a 48-volt mild-hybrid system (EQ Boost). The EQ Boost system incorporates an integrated starter-generator (ISG) that adds 22 hp and 250 Nm (184.39 lb.-ft.) of torque, providing assistance during acceleration and enabling a smoother start/stop function. The engine utilizes direct fuel injection and a twin-scroll turbocharger with intercooling to achieve a power output of 367 hp at 5,500-6,100 rpm and 500 Nm (368.78 lb.-ft.) of torque between 1,600-4,500 rpm. The compression ratio is 10.5:1, and the engine features a double overhead camshaft (DOHC) valvetrain with four valves per cylinder.

The 9G-TRONIC automatic transmission, a nine-speed unit, is specifically tuned to complement the characteristics of the M 256 engine. This transmission offers smooth and precise gear changes, contributing to both driving comfort and fuel efficiency. The transmission’s gear ratios are optimized for both acceleration and highway cruising, providing a balance between responsiveness and relaxed operation. The 4MATIC all-wheel-drive system distributes power between the front and rear axles, enhancing traction and stability in various driving conditions.

Engine Codes & Variations

While the core M 256.930 engine remained consistent, slight variations in engine management software and calibration may have existed depending on the specific market and emissions regulations. The EQ Boost system was a standard feature on all S 450 4MATIC models produced during this period, differentiating it from earlier S-Class generations.

Driving Characteristics

The S 450 4MATIC delivers a driving experience characterized by smoothness, refinement, and effortless power. The combination of the inline-six engine and the 9G-TRONIC transmission provides ample acceleration, with a 0-60 mph time of approximately 4.8 seconds and a 0-100 km/h time of 5.1 seconds. The EQ Boost system provides an immediate boost of torque, enhancing responsiveness during overtaking maneuvers and initial acceleration. Compared to the more powerful S 580 models, the S 450 4MATIC offers a slightly less aggressive driving experience, prioritizing comfort and fuel efficiency. The all-wheel-drive system provides confident handling in all weather conditions, while the air suspension contributes to a remarkably smooth ride quality.

The 9G-TRONIC transmission’s gear ratios are well-spaced, allowing the engine to operate efficiently at various speeds. In typical driving scenarios, the transmission seamlessly shifts through the gears, providing a relaxed and comfortable experience. Drivers can also manually select gears using the steering wheel-mounted paddle shifters for more engaging control.

Equipment & Trim Levels

The S 450 4MATIC came standard with a comprehensive array of luxury features, befitting its position in the S-Class range. Standard equipment typically included leather upholstery, heated and ventilated front seats with massage functions, a premium sound system, a large touchscreen infotainment system with Mercedes-Benz’s MBUX interface, and a suite of advanced driver-assistance systems, such as adaptive cruise control, lane-keeping assist, and automatic emergency braking. Interior trim options included a variety of wood veneers, aluminum accents, and leather colors.

Optional extras included features such as a rear-seat entertainment system, a panoramic sunroof, upgraded leather upholstery, and various customization options through Mercedes-Benz’s Designo program. The S 450 4MATIC could also be equipped with features like the Executive Rear Seat Package, which added features like reclining rear seats and a center console with controls for the rear passengers.

Chassis & Braking

The W223 S-Class, including the S 450 4MATIC, features a sophisticated chassis design focused on ride comfort and handling. The suspension system utilizes an independent multi-link setup at both the front and rear, coupled with Mercedes-Benz’s AIRMATIC air suspension. The air suspension allows for adjustable ride height and damping, providing a smooth and controlled ride even on uneven surfaces. The S 450 4MATIC is equipped with ventilated disc brakes on all four wheels, providing ample stopping power. Additional safety features include ABS (Anti-lock Braking System) and 4-wheel steering (4WS, active rear steering) which enhances maneuverability at low speeds and stability at high speeds.

Market Reception & Comparison

The S 450 4MATIC was generally well-received by automotive critics, who praised its refined driving experience, luxurious interior, and advanced technology. It was often positioned as the sweet spot in the S-Class lineup, offering a compelling balance of performance, comfort, and value. Fuel economy, rated between 7.8-9.4 l/100 km (30.2 – 25 US mpg), was considered competitive for a vehicle of its size and class. Compared to the S 580, the S 450 4MATIC offered a slightly lower price point and better fuel economy, while still providing a luxurious and capable driving experience. Reliability reports have been generally positive, with the M 256 engine proving to be a robust and dependable unit.

Technical Specifications

Legacy

The S 450 4MATIC (W223) represents a technologically advanced and refined iteration of the iconic S-Class. The M 256 engine, with its EQ Boost mild-hybrid system, proved to be a reliable and efficient powertrain. On the used car market, these models are generally sought after for their combination of luxury, performance, and technology. The W223 S-Class, and specifically the S 450 4MATIC, is expected to maintain its position as a desirable luxury sedan for years to come, offering a compelling blend of comfort, technology, and prestige.