Mercedes-Benz has long been synonymous with luxury and innovation, and the 2010 S400 HYBRID model marked a significant step forward, blending these hallmarks with groundbreaking hybrid technology. This model wasn’t just another addition to the prestigious S-Class lineup; it was a statement about the future of luxury automobiles, proving that power and environmental consciousness could coexist. The S400 Mercedes arrived boasting V8-level performance while introducing the world’s first lithium-ion battery specifically engineered for automotive applications. This innovation, coupled with a potent electric motor and a refined V6 gasoline engine, delivered a hybrid experience that was both powerful and surprisingly fuel-efficient.
The Mercedes-Benz S-Class itself is often regarded as the pinnacle of automotive excellence, the standard by which other luxury sedans are measured. The S400 Mercedes slotted into this esteemed family alongside the restyled 2010 S-Class models. This included the robust V8-powered S550 and its all-wheel-drive counterpart, the S550 4MATIC, as well as the high-performance S63 AMG. For those seeking ultimate power, the V12 variants, the S600 and the S65 AMG, remained at the top of the range.
Refreshed Styling Across the 2010 S-Class Range
The entire 2010 S-Class sedan lineup, including the S400 Mercedes, received a styling refresh, enhancing its already sophisticated appearance. The updates included a more streamlined front grille, contributing to a sleeker and more modern aesthetic. Larger side mirrors improved visibility and presence, while a redesigned front bumper, accented with a chrome strip beneath the air intakes, added a touch of elegance. The new active bi-xenon headlights incorporated LED turn signals along their lower edge, further emphasizing the car’s contemporary design.
While most 2010 S-Class models adopted LED daytime running lights on each side of the bumper, the S400 Mercedes was an exception. However, all models shared other exterior enhancements, including updated LED tail lights and exhaust outlets seamlessly integrated into a re-contoured rear bumper.
Inside the cabin, the 2010 S-Class, including the S400 Mercedes, featured an upgraded wood and premium-leather steering wheel, elevating the tactile experience for the driver. Standard ambient lighting offered a customizable atmosphere with three selectable hues: polar (ice-blue), neutral (white), and solar (amber), allowing occupants to tailor the interior mood. For rear passengers, a new rear-seat entertainment system became available, enhancing the luxury experience for everyone on board.
Groundbreaking Safety Innovations in the 2010 S-Class
Mercedes-Benz has always been at the forefront of automotive safety, and the 2010 S-Class, including the S400 Mercedes, was no exception. It introduced six new safety features designed to potentially save lives. These advancements included ATTENTION ASSIST, Lane-Keeping Assist, Nightview Assist Plus with pedestrian detection, Adaptive Highbeam Assist, and PRE-SAFE Brake, now enhanced with full 100-percent braking capability in emergency situations. Furthermore, the ABC active suspension system incorporated a new crosswind stabilization system, enhancing vehicle control in challenging conditions.
ATTENTION ASSIST: Detecting Driver Drowsiness
One of the most innovative features, ATTENTION ASSIST, became standard on all S-Class models except the S400 Mercedes (note: original article contradicts itself here, stating it’s standard on all except S400 HYBRID, then later states it’s not standard on S400 HYBRID. We will assume it’s not standard on S400 HYBRID based on later clarification). This system was designed to combat driver fatigue, a major cause of accidents. By monitoring steering behavior and analyzing over 70 parameters, ATTENTION ASSIST learns a driver’s unique profile during the initial 20 minutes of a journey. Between 50 and 112 mph, it can detect the subtle, erratic steering corrections that indicate drowsiness. If detected, the system issues an audible warning and displays a “Time for a rest?” message with a coffee cup icon in the instrument cluster.
Advanced Driver Assistance Systems
Lane Keeping Assist further enhanced safety by alerting drivers if they unintentionally drift out of their lane without using turn signals. Above 37 mph, the system utilizes a multi-purpose camera to recognize lane markings and provides tactile feedback through steering wheel vibrations, mimicking rumble strips.
Adaptive Highbeam Assist utilized the same camera technology to detect headlights and taillights of other vehicles. It then automatically and smoothly adjusts between high and low beams to prevent dazzling other drivers, optimizing visibility while ensuring consideration for oncoming traffic. This system offered a variable headlight range from 220 feet up to an impressive 1,000 feet.
Night View Assist PLUS took nighttime visibility to a new level, enabling drivers to detect pedestrians up to 325 feet earlier than with conventional systems. When pedestrians are recognized, they are highlighted with an outlined frame in the display. Unlike passive thermal imaging systems, this active system uses invisible infrared light emitted from two beams in the headlights to illuminate the road ahead, extending the driver’s vision to nearly 500 feet. The system displays highly detailed black and white video images in the instrument cluster, derived from an infrared camera mounted in the windshield.
PRE-SAFE® Brake: Automatic Emergency Braking
The PRE-SAFE® Brake system, available on models equipped with DISTRONIC PLUS, represented another significant leap in safety technology. This advanced system could automatically apply full braking in emergency situations to mitigate or prevent collisions.
When PRE-SAFE Brake detects an impending collision using DISTRONIC PLUS radar, it initiates a series of warnings. Approximately 1.6 seconds before a likely impact, it sounds three warning tones and automatically applies partial braking, while also activating PRE-SAFE occupant protection measures. If the driver still doesn’t react, full-power braking is engaged about 0.6 seconds before the predicted collision, effectively acting as an “electronic crumple zone” to reduce impact severity.
PRE-SAFE Brake built upon the foundation of the original PRE-SAFE system introduced by Mercedes-Benz in 2002. The basic PRE-SAFE system, standard on all S-Class models, proactively tightens front seat belts and adjusts seat positions in the moments before a potential impact. It also closes the sunroof and side windows if a rollover is detected and can inflate special seat cushions to enhance lateral support and airbag effectiveness.
DISTRONIC PLUS also incorporated Blind Spot Assist, monitoring blind spots and providing visual and audible warnings when a turn signal is activated with a vehicle in a blind spot. Furthermore, the radar-based Distronic Plus system enabled Parking Guidance as part of the Parktronic system. At low speeds, Parking Guidance scans for suitable parking spaces and indicates availability. When reversing, it provides a top-view pictogram and steering guidance to assist with parking maneuvers.
For 2010 S-Class models with ABC active suspension, a new crosswind stabilization feature was integrated into the ABC system software. This system instantaneously counteracts crosswinds by adjusting wheel load distribution via suspension servo pistons, enhancing vehicle stability. Crosswind stabilization relies on networked signals from ESC yaw and lateral-acceleration sensors.
Direct-steer, also new for 2010, employed variable-ratio gearing in the steering rack to provide enhanced on-center steering feel and increased responsiveness beyond the initial steering angle. This mechanical system reduced steering input needed during cornering and low-speed maneuvers, like parking.
Torque Vectoring Brake, standard on all S-Class models except the S400 Mercedes, further enhanced handling. This ESC system feature applied brief braking pulses to the inside rear wheel during aggressive steering inputs, aiding vehicle pivot and improving handling response during spirited driving.
The S400 HYBRID: Efficiency Without Compromise
The heart of the S400 Mercedes was its innovative hybrid powertrain. It utilized a 3.5-liter V6 gasoline engine, an electric motor, and sophisticated hybrid electronics to achieve a remarkable 30 percent improvement in fuel economy compared to a comparable S550 model. The electric motor, while compact, delivered 20 horsepower and an impressive 118 lb.-ft. of starting torque. Combined with the gasoline engine’s 275 hp and 258 lb.-ft. of torque, the S400 Mercedes offered a compelling blend of power and efficiency.
A sophisticated computer system managed the hybrid system, performing calculations 160 times per second to optimize performance and fuel economy. This system could execute up to 50 million calculations per second, ensuring seamless transitions between operating modes.
The 120-volt lithium-ion battery, a world-first for automotive applications, was a key component of the S400 Mercedes hybrid system. It was lighter and more compact than traditional batteries yet offered high energy density. This allowed for its placement in the engine compartment without compromising trunk space or interior room. The battery featured a high-strength steel housing, a dedicated cooling circuit, and cells embedded in a special gel to dampen shocks and vibrations.
Classified as a “mild hybrid,” the S400 Mercedes employed a system where the gasoline engine and electric motor worked in concert for responsive performance. The driveline incorporated a specially adapted seven-speed automatic transmission, a transformer for the 12-volt vehicle system, and intelligent operating electronics. The disc-shaped electric motor was positioned within the torque converter housing, between the engine and transmission.
The hybrid system included a start-stop function that automatically shut off the gasoline engine below nine mph when braking to a stop, such as at traffic lights. During engine shut-off, the AC compressor and steering pump remained electrically powered, ensuring continued air conditioning and power steering functionality. Upon releasing the brakes, the gasoline engine restarted automatically, seamlessly integrating with the electric motor for smooth performance.
During braking, the electric motor functioned as a generator, recuperating kinetic energy and storing it in the lithium-ion battery. Conventional brakes also engaged during heavier braking. The recovered energy was then reused by the electric motor, enhancing overall efficiency.
Atkinson-Cycle Engine Optimization
Mercedes-Benz engineers optimized the 3.5-liter V6 engine for fuel efficiency by employing the Atkinson principle. By delaying the closing of the intake valves, the intake stroke became effectively longer than the compression stroke, improving thermal efficiency and reducing fuel consumption and emissions.
While Atkinson engines typically produce less low-speed torque, this characteristic was ideally suited for a hybrid vehicle like the S400 Mercedes. The electric motor effectively compensated for this by supplementing the V6 engine’s low-end torque, ensuring excellent throttle response during acceleration. The Atkinson-cycle V6 engine featured specific cylinder heads, pistons, camshafts, modified variable valve timing control, and a low-load oil pump, all contributing to enhanced fuel economy.
Uncompromised Luxury and Convenience
The S400 Mercedes retained the same levels of interior space, luxury appointments, and convenience features as other S-Class models. Distinguishing features included unique seven-twin-spoke 18-inch wheels and HYBRID logos on the trunk lid and dashboard, along with BlueEfficency badging on the front fenders. A special hybrid pictogram within the speedometer displayed energy flow, energy recovery, and battery charge status.
DISTRONIC PLUS: Easing Stop-and-Go Traffic
The DISTRONIC PLUS adaptive cruise control system utilized radar sensors to maintain a preset following distance. The advanced system could bring the car to a complete stop and automatically resume acceleration, proving particularly useful in stop-and-go traffic. DISTRONIC PLUS operated at speeds up to 125 mph. It employed both short-range 24-gigahertz and longer-range 77-gigahertz radar frequencies to cover a comprehensive range of over 160 yards, enhancing its effectiveness in various traffic situations.
Brake Assist and Brake Assist PLUS
Mercedes-Benz pioneered Brake Assist technology based on the discovery that many drivers don’t apply sufficient braking force in emergencies. Brake Assist, standard on Mercedes-Benz vehicles since the late 1990s, has proven highly effective in accident reduction.
On the S-Class models equipped with Distronic Plus, Brake Assist Plus further enhanced braking performance. It not only provided emergency braking assistance when the brake pedal was applied rapidly but also measured the distance to the vehicle ahead and adjusted brake pressure if the driver’s braking was insufficient. Unlike conventional Brake Assist, which was triggered by brake pedal speed, Brake Assist Plus also considered the closing speed to the vehicle ahead using radar signals from Distronic Plus.
Adaptive Brake Lights and Advanced Technology
The S600 and S65 AMG models featured adaptive brake lights that flashed rapidly during emergency braking, a feature designed to reduce rear-end collisions. These rapidly flashing LED brake lights were activated primarily by the car’s Brake Assist system.
The S-Class also incorporated advanced technology throughout, including an audio head unit capable of reading data from USB sticks or SD cards. This system allowed for playback of digital music libraries, controllable via the multifunction steering wheel. The audio head unit featured integrated Bluetooth, HD radio, a 7.2-gigabyte Music Register, SIRIUS-XM satellite radio with real-time traffic data, and Zagat hotel, restaurant, and golf rating information.
AMG Styling and V12 Power
The S63 AMG model showcased exclusive AMG body styling, alloy wheels, sports suspension, and a high-performance brake system. A distinctive front bumper with large air intakes and LED daytime running lights, AMG badging, contoured side skirts, and an AMG rear apron with twin tailpipes contributed to its aggressive and sporty appearance. Inside, the S63 AMG featured an AMG sport steering wheel, multi-contour leather sport seats, and an exclusive analog clock. The AMG suspension and brake systems were tuned for high-performance driving, with selectable transmission shift programs and ABC active suspension settings.
The V12-powered S-Class models, the S600 and S65 AMG, represented the pinnacle of performance and luxury. The S600, powered by a twin-turbo V12 engine, delivered immense power with exceptional refinement. The S65 AMG, developed by AMG, featured an even more powerful twin-turbo V12, making it the world’s quickest four-door sedan at the time. AMG enhancements extended to the exterior and interior styling, with unique AMG aprons, side skirts, wheels, and interior appointments.
Conclusion: The S400 Mercedes – A Hybrid Pioneer
The S400 Mercedes represented a bold step into the future of luxury motoring. It successfully combined the opulence and sophistication of the S-Class with innovative hybrid technology, delivering impressive fuel economy without sacrificing performance or comfort. As the world’s first automotive application of a lithium-ion battery, the S400 Mercedes was not just a luxury sedan; it was a technological statement, paving the way for future generations of efficient and powerful vehicles. For those seeking a blend of high-end luxury and environmental consciousness, the S400 Mercedes stood out as a pioneering and compelling choice.
