2021 Mercedes-Benz CLS: Elegant Design and Features

The 2021 Mercedes-Benz CLS redefines the concept of a luxury four-door coupe with its blend of timeless design, intelligent technology, and refined performance. This third-generation model carries forward the CLS legacy of elegant proportions, sleek aerodynamics, and luxurious minimalism while incorporating advanced mild-hybrid powertrains and MBUX digital integration. With its sculpted lines, four-cylinder and inline-six engines, and a meticulously crafted interior, the 2021 CLS is engineered for discerning drivers who value both style and substance.

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What’s New for the 2021 Mercedes-Benz CLS: Design and Powertrain Updates

The 2021 Mercedes-Benz CLS refines its identity as a four-door coupe that merges elegance, innovation, and performance. Positioned between the E-Class and S-Class, the CLS benefits from key updates that improve aesthetics, powertrain efficiency, and onboard intelligence. For 2021, Mercedes introduced a facelift with design enhancements, new mild-hybrid technology (EQ Boost), and the latest iteration of the MBUX infotainment system, ensuring that the CLS remains both timeless and technologically advanced.

Design Refinements and Visual Evolution

Externally, the 2021 CLS gains a sharper, more aerodynamic profile. The diamond-pattern front grille now features a chrome finish and an integrated Mercedes star mesh pattern, giving the coupe a bolder stance. Revised air intakes and LED Multibeam headlamps enhance both visual appeal and visibility. At the rear, the slimmer taillight cluster and new bumper design create a cleaner, wider impression.

Mercedes also introduced new 19- and 20-inch alloy wheels with optimized aerodynamics and reduced rolling resistance. Paint options now include Spectral Blue Metallic and Designo Patagonia Red, expanding personalization choices.

Update Area	2020 CLS	2021 CLS
Engine Technology	Standard turbo	EQ Boost mild-hybrid (48V)
Infotainment	COMAND system	MBUX with AI voice assistant
Headlights	LED	Multibeam LED (adaptive)
Grille Design	Standard diamond	Star-pattern grille
Interior Trim	Piano black	Open-pore walnut and carbon fiber

Powertrain and Efficiency Enhancements

Under the hood, the CLS 450 4MATIC introduces the 3.0-liter inline-six turbo engine with EQ Boost mild-hybrid assistance. The system adds up to 21 hp and 250 Nm of torque during acceleration via an integrated starter-generator (ISG), while also enabling coasting and energy recuperation for improved efficiency. The 9G-Tronic automatic transmission ensures seamless gear shifts and supports the hybrid system’s electric functions.

Meanwhile, the CLS 300d continues to offer a refined 2.0-liter OM654 diesel, featuring reduced emissions and smoother operation through optimized injection and SCR catalytic technology.

Interior and Technology Improvements

Inside, the cabin adopts a new two-tone color scheme and updated steering wheel with capacitive controls. The MBUX infotainment system replaces COMAND, offering a 12.3-inch touchscreen with AI-based voice commands, augmented reality navigation, and OTA updates. Wireless charging, advanced ambient lighting, and new ENERGIZING Comfort programs enhance the luxury experience.

Update Highlights:

• EQ Boost hybrid tech improving efficiency and response
• MBUX infotainment replacing COMAND system
• Refined LED lighting and aerodynamic grille design
• Revised cabin materials with enhanced comfort options
• Expanded wheel and color selection for personalization

The 2021 Mercedes-Benz CLS perfectly balances heritage with modern innovation. Its updates reflect Mercedes’ evolution toward electrified performance, digital intelligence, and enduring elegance — ensuring the CLS remains a benchmark in its segment.

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Engine Options, Transmission, and Real-World Performance

The 2021 Mercedes-Benz CLS continues to combine efficiency and performance through a refined lineup of mild-hybrid gasoline and high-efficiency diesel engines. Built on the MRA platform, every CLS variant is engineered for smooth power delivery, exceptional refinement, and quiet operation — all trademarks of Mercedes’ advanced powertrain philosophy.

Powertrain Lineup and EQ Boost Integration

Mercedes offers three main powertrains for the 2021 CLS, each tuned for a unique blend of responsiveness and fuel efficiency. The highlight is the introduction of the EQ Boost 48-volt mild-hybrid system, integrated directly into the transmission via the Integrated Starter Generator (ISG). This setup allows the electric motor to add temporary torque while enabling coasting and seamless start/stop transitions.

Variant	Engine Type	Power Output	Torque	Drivetrain	Transmission
CLS 300	2.0L I4 turbo petrol	258 hp (190 kW)	370 Nm	RWD	9G-Tronic
CLS 400d 4MATIC	3.0L I6 turbo diesel	330 hp (243 kW)	700 Nm	AWD	9G-Tronic
CLS 450 4MATIC	3.0L I6 turbo petrol + EQ Boost	367 hp (270 kW) + 21 hp (ISG)	500 Nm + 250 Nm (electric assist)	AWD	9G-Tronic

The CLS 450 4MATIC stands out as the flagship model, featuring Mercedes’ innovative EQ Boost technology. The electric motor fills torque gaps during acceleration, effectively eliminating turbo lag, and contributes to smoother transitions at low speeds.

Transmission and Driving Dynamics

All engines are paired with the 9G-Tronic automatic transmission, known for its swift, nearly imperceptible shifts. Gear ratios are optimized for both performance and fuel economy — low gears deliver instant response, while higher gears reduce RPM during cruising. The 4MATIC all-wheel-drive system distributes torque intelligently between the axles, enhancing grip and stability in wet or dynamic driving conditions.

The electromechanical steering system improves agility and precision, while the Dynamic Select drive modes (Comfort, Sport, Sport+, Eco, and Individual) tailor throttle response, suspension damping, and steering effort to match driver preference.

Performance Highlights:

• EQ Boost 48V hybrid adds instant torque and smoother acceleration
• 9G-Tronic transmission with rapid adaptive shifts
• 4MATIC AWD system optimizing traction and cornering stability
• Dynamic Select modes customizing performance behavior
• Up to 700 Nm torque (in CLS 400d) for effortless high-speed cruising

Real-World Performance and Refinement

On the road, the CLS impresses with its composure and fluidity. The CLS 450 accelerates from 0–100 km/h in 4.8 seconds, delivering performance on par with a sports sedan, while maintaining serene refinement at highway speeds. The inline-six architecture provides natural balance, minimizing vibration and maximizing smoothness — a signature of Mercedes engineering.

Even at full throttle, the cabin remains impressively quiet, thanks to acoustic insulation and optimized engine mounts. Combined with the intelligent powertrain calibration, the 2021 CLS delivers an ideal fusion of performance and serenity, making it as engaging as it is elegant.

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Driving Experience, Handling, and Ride Comfort

The 2021 Mercedes-Benz CLS masterfully blends grand-touring comfort with agile dynamics, creating a driving experience that is both refined and rewarding. Sitting between the E-Class and S-Class in Mercedes’ lineup, the CLS offers a balanced mix of sportiness and serenity, supported by cutting-edge suspension technology, adaptive damping, and 4MATIC all-wheel-drive precision.

Ride Comfort and Suspension Setup

Mercedes engineers have fine-tuned the CLS to deliver smooth, poised handling without compromising ride comfort. The AIRMATIC air suspension automatically adjusts damping and ride height depending on load and road conditions, ensuring that the vehicle glides over imperfections while maintaining composure at high speeds.

In Comfort mode, the suspension isolates occupants from rough surfaces with exceptional smoothness, while switching to Sport or Sport+ introduces firmer damping for sharper response. The adaptive system continuously analyzes road texture, cornering force, and steering input via sensors, adjusting shock absorber stiffness in milliseconds.

The result is a seamless transition between comfort and agility — one of the CLS’s defining traits that sets it apart from conventional sedans.

Steering Precision and Cornering Dynamics

The electromechanical steering provides light yet precise feedback, enhancing maneuverability at low speeds and stability during highway driving. When combined with the 4MATIC torque distribution system, the CLS maintains impressive traction in both wet and dry conditions. The system continuously monitors wheel slip, transferring torque between axles to prevent understeer or loss of grip.

Driving Highlights:

• AIRMATIC adaptive suspension balancing comfort and control
• 4MATIC AWD system improving traction and stability
• Dynamic Select drive modes for tailored performance
• Precise electromechanical steering enhancing feedback
• Advanced NVH insulation minimizing cabin vibration

Highway Refinement and Everyday Usability

The CLS is designed for long-distance travel as much as it is for spirited driving. On highways, the car feels effortless, with the 9G-Tronic transmission keeping the engine in its most efficient range while reducing cabin noise. At 120 km/h, engine revolutions hover around 1,700 rpm, contributing to a tranquil driving environment.

The NVH (Noise, Vibration, and Harshness) control is exemplary — double-glazed windows, optimized aerodynamics, and underbody sealing keep wind and road noise at luxury-class levels. Even during hard acceleration, the inline-six engine emits a subdued yet authoritative growl, reinforcing the coupe’s refined character.

The driving experience of the 2021 Mercedes-Benz CLS is defined by its dual personality: graceful enough for daily commutes, yet dynamic enough to excite enthusiasts. It’s the embodiment of Mercedes’ philosophy — blending performance engineering with effortless sophistication.

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Interior Design, Materials, and Smart Cabin Features

The 2021 Mercedes-Benz CLS interior embodies modern luxury, showcasing meticulous craftsmanship and cutting-edge digital innovation. Every element — from the sculpted dashboard to the seamless MBUX interface — is designed to immerse occupants in a premium driving environment that balances sophistication with functionality.

Cabin Layout and Material Quality

The CLS inherits its design philosophy from the S-Class, featuring a wraparound cockpit with flowing lines and ambient light integration. The dashboard is dominated by dual 12.3-inch high-resolution displays, merging the digital instrument cluster and infotainment screen into a panoramic unit under a single glass panel.

Materials are of unmistakable Mercedes quality: Nappa leather, open-pore walnut, carbon fiber, and brushed aluminum trims elevate the cabin to an artful standard. Soft-touch surfaces extend across the door panels and center console, while subtle chrome accents highlight air vents and seat controls.

Interior Dimension / Feature	Measurement / Detail
Front Legroom	1,060 mm
Rear Legroom	895 mm
Headroom (Front / Rear)	980 mm / 940 mm
Trunk Capacity	490 liters
Display Size	Dual 12.3” MBUX Screens
Ambient Lighting	64-color LED with dynamic themes

Technology and Digital Interface

At the core of the CLS’s interior experience lies the MBUX (Mercedes-Benz User Experience) system. Its AI-based voice control understands natural speech commands — simply say “Hey Mercedes” to adjust climate settings, navigate routes, or manage media playback. The system also learns user preferences over time, adapting menu shortcuts and driver profiles.

Additional digital highlights include augmented reality navigation, wireless smartphone charging, and Apple CarPlay / Android Auto integration. The head-up display projects key information onto the windshield, allowing the driver to remain focused on the road.

Interior Highlights:

• Dual 12.3-inch digital displays with unified glass housing
• AI-powered MBUX voice assistant and AR navigation
• 64-color ambient lighting for mood personalization
• Wireless charging and smartphone mirroring
• Nappa leather upholstery and premium interior trims

Comfort and Ergonomic Design

The CLS offers seating comfort befitting its coupe-luxury status. The multi-contour front seats feature active side bolsters, heating, ventilation, and massage functions — all adjustable through the infotainment screen or voice command. Rear passengers enjoy sculpted seats with generous support and dual climate zones for personalized comfort.

Noise insulation is exemplary, supported by acoustic glass and active sound management, ensuring a tranquil cabin environment. The ENERGIZING Comfort Control system syncs climate, seat massage, ambient light, and music profiles to enhance well-being during long drives.

Inside the 2021 Mercedes-Benz CLS, luxury is not just seen — it’s experienced. The seamless fusion of technology, craftsmanship, and ergonomics transforms every journey into an elegant, effortless experience.

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Safety and Driver Assistance: Mercedes Intelligent Systems

The 2021 Mercedes-Benz CLS reaffirms the brand’s commitment to intelligent safety through an extensive suite of both active and passive protection systems. Combining radar, camera, and sensor-based technologies under the Mercedes Intelligent Drive umbrella, the CLS constantly monitors its surroundings to prevent collisions, support the driver, and safeguard occupants in any driving scenario.

Advanced Driver Assistance Features

For 2021, the CLS receives the latest version of Mercedes’ Driver Assistance Package Plus, integrating adaptive sensors and real-time situational mapping. The system leverages data from multi-mode radar units, stereo cameras, and ultrasonic detectors to manage everything from traffic navigation to evasive maneuvers.

Feature	Function	Description
Active Distance Assist DISTRONIC	Adaptive cruise control	Maintains distance from vehicle ahead using radar and throttle control
Active Steering Assist	Lane-centering	Keeps the CLS within its lane during curves or traffic congestion
Active Brake Assist	Collision avoidance	Warns of potential collisions and applies automatic braking if needed
Evasive Steering Assist	Emergency maneuvering	Enhances steering precision during sudden obstacle avoidance
PRE-SAFE® System	Collision preparation	Tightens seatbelts, adjusts seat position, and closes windows pre-impact
Blind Spot Assist	Side awareness	Warns of vehicles in adjacent lanes via mirror indicators

The Traffic Sign Assist and Active Lane Keeping Assist features complement these systems, ensuring compliance with speed limits and maintaining safe lane discipline even in challenging weather.

Passive Safety and Structural Integrity

Mercedes engineers designed the CLS body with a high-strength steel and aluminum hybrid structure, providing exceptional rigidity while minimizing weight. Crumple zones are strategically engineered to absorb impact energy, while the reinforced passenger cell protects occupants with minimal deformation.

Multiple airbags — including frontal, thorax, curtain, and knee units — create a cocoon of protection in the event of a collision. Additionally, Active Bonnet technology raises the hood slightly upon pedestrian impact, reducing injury severity.

Safety Highlights:

• Mercedes Intelligent Drive with advanced semi-autonomous systems
• Active Brake and Steering Assist for proactive accident prevention
• PRE-SAFE® collision mitigation system with preemptive safety actions
• High-strength hybrid body shell for improved impact absorption
• Comprehensive airbag suite and pedestrian protection measures

Real-World Confidence and Predictive Protection

The CLS demonstrates remarkable stability through the ESP Dynamic Control and Crosswind Assist systems, maintaining composure even in high-speed crosswinds or wet conditions. The car’s 4MATIC AWD system and Adaptive Brake technology further enhance control under variable traction surfaces.

Drivers benefit from predictive alerts via the digital cockpit, while night-time visibility is enhanced through Multibeam LED headlamps with Adaptive Highbeam Assist Plus — adjusting beam distribution dynamically to prevent glare for oncoming traffic.

Ultimately, the 2021 Mercedes-Benz CLS sets the benchmark for intelligent safety in its class, combining passive resilience with active foresight to deliver a driving experience that prioritizes confidence, protection, and peace of mind.

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Infotainment and Connectivity: Inside the MBUX Experience

The 2021 Mercedes-Benz CLS brings digital luxury to the forefront with the latest generation of the MBUX infotainment system, integrating intelligent connectivity, customizable interfaces, and voice-controlled functions. This platform transforms the CLS from a driver’s car into a fully connected digital environment, redefining how technology interacts with human intuition.

MBUX Interface and System Overview

Replacing the previous COMAND setup, MBUX (Mercedes-Benz User Experience) introduces a seamless digital ecosystem based on AI learning algorithms. The centerpiece is a pair of 12.3-inch HD displays arranged in a widescreen configuration — one serving as a digital instrument cluster, the other as the central infotainment hub.

Feature Category	Previous COMAND	MBUX (2021)
Screen Layout	10.25-inch dual	12.3-inch dual widescreen
Voice Assistant	Limited commands	AI-based natural speech (“Hey Mercedes”)
Navigation	SD-based maps	Augmented reality GPS with OTA updates
Connectivity	Bluetooth only	Wi-Fi, LTE, Apple CarPlay, Android Auto
Interface Type	Rotary dial	Touchscreen + Touchpad + Voice Control

This triple-control setup allows users to interact through touch, gesture, or voice, ensuring intuitive operation without distraction. The MBUX voice assistant uses natural language understanding, enabling commands like “Hey Mercedes, take me home” or “Change the interior lighting to blue”.

Connectivity and Smart Features

The Mercedes Me Connect app extends the CLS’s intelligence beyond the cabin, allowing remote access to vehicle data, locking functions, and climate pre-conditioning. Drivers can check fuel levels, service notifications, and location tracking directly from their smartphone.

Over-The-Air (OTA) software updates keep navigation and driver-assistance features up to date without dealership visits. The augmented reality navigation projects route information directly onto a live camera feed, overlaying arrows and directions on the screen for clear guidance in complex intersections.

Connectivity Highlights:

• AI-powered MBUX voice assistant for hands-free operation
• Dual 12.3-inch digital displays for immersive control
• Augmented reality navigation with real-time overlay
• Mercedes Me Connect app for remote vehicle management
• OTA updates ensuring software remains current

Entertainment and Cabin Interaction

Audio excellence is delivered through the optional Burmester® 3D Surround Sound System, producing crystal-clear acoustics with 13 high-performance speakers and a 590-watt amplifier. Wireless smartphone charging, five USB-C ports, and integrated Wi-Fi hotspot capability ensure connectivity for all occupants.

Ambient light themes can be linked to audio and climate functions — for example, intensifying illumination when volume rises or temperature changes. Together, these subtle digital cues make the driving environment more dynamic and engaging.

In sum, the 2021 Mercedes-Benz CLS brings connectivity to an art form — combining voice intelligence, digital craftsmanship, and real-world convenience. It’s not just infotainment; it’s interactive luxury, designed to anticipate every need with elegant precision.

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Fuel Efficiency and Hybrid Technology Integration

The 2021 Mercedes-Benz CLS demonstrates that performance and efficiency can coexist harmoniously. Thanks to the implementation of EQ Boost mild-hybrid technology, aerodynamic refinement, and intelligent drivetrain management, the CLS achieves remarkable fuel economy without compromising its hallmark smoothness and power delivery.

EQ Boost System: How It Works

At the heart of the CLS’s efficiency lies the EQ Boost 48-volt mild-hybrid system. Integrated into the 9G-Tronic transmission, the Integrated Starter Generator (ISG) replaces both the conventional alternator and starter motor. This compact electric unit assists the internal combustion engine by providing up to 21 hp (16 kW) and 250 Nm of torque instantly during acceleration.

During coasting or braking, the ISG recovers kinetic energy and stores it in the 48V lithium-ion battery, powering auxiliary systems like air conditioning, lighting, and infotainment without burdening the engine. The system also enables seamless engine restarts, sailing mode, and engine-off coasting, enhancing comfort and fuel savings.

Variant	Engine	Transmission	WLTP Combined	CO₂ Emissions
CLS 300	2.0L I4 turbo petrol	9G-Tronic	7.2 L/100 km	165 g/km
CLS 400d 4MATIC	3.0L I6 diesel	9G-Tronic	6.3 L/100 km	148 g/km
CLS 450 4MATIC (EQ Boost)**	3.0L I6 petrol + hybrid assist	9G-Tronic	7.6 L/100 km	173 g/km

(Figures may vary depending on configuration and tire size.)

Real-World Efficiency and Driving Behavior

In daily driving, the CLS benefits significantly from the coasting function, where the engine switches off completely when cruising under light throttle. The Eco Start/Stop system operates imperceptibly, assisted by the ISG’s instant torque fill, making transitions between electric assist and combustion power seamless.

Drivers typically achieve real-world consumption between 7.0–7.8 L/100 km in petrol models and 6.0–6.5 L/100 km in diesel variants. This level of efficiency is especially impressive given the vehicle’s weight, AWD configuration, and luxury equipment.

Efficiency Highlights:

• EQ Boost 48V system offering torque assist and energy recovery
• Coasting and sailing functions reducing fuel usage at cruising speeds
• Intelligent alternator management powering electrical systems efficiently
• Eco Start/Stop with ISG for seamless transitions
• Up to 15% improvement in overall fuel efficiency versus pre-facelift models

Aerodynamic Optimization and Sustainable Design

The CLS’s Cd value of 0.26 ranks among the lowest in its class, contributing directly to lower fuel consumption and reduced wind noise. Lightweight aluminum components in the hood and suspension help minimize inertia, improving overall efficiency.

Mercedes also integrates low-rolling-resistance tires and smart grille shutters that automatically close at high speeds to enhance aerodynamics. Together, these elements form a holistic efficiency ecosystem — where technology, design, and sustainability merge seamlessly.

The 2021 Mercedes-Benz CLS exemplifies modern luxury reimagined for a responsible future — dynamic, efficient, and electrified through precision German engineering.

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Dimensions, Cargo Space, and Practical Usability

The 2021 Mercedes-Benz CLS combines elegant proportions with practical usability, proving that a coupe-inspired design can still deliver everyday functionality. Its sleek, fastback profile conceals a spacious cabin and a surprisingly accommodating trunk — designed with both aesthetic balance and ergonomic precision in mind.

Exterior Dimensions and Proportional Balance

The CLS is built upon Mercedes’ MRA platform, which supports optimal rigidity, aerodynamic efficiency, and interior space. Its elongated hood, short overhangs, and sweeping roofline create a dynamic silhouette while maintaining comfort and usability for daily driving.

Specification	Measurement
Overall Length	4,982 mm
Width (w/ mirrors)	2,068 mm
Height	1,435 mm
Wheelbase	2,939 mm
Ground Clearance	120 mm
Curb Weight	1,845–1,920 kg
Trunk Capacity	490 liters

Despite its low stance, the CLS’s wide track width enhances stability, and the long 2.94-meter wheelbase ensures generous legroom for both front and rear passengers. The frameless doors and sloping C-pillar design give the car its signature coupe character while maintaining practical ingress and egress angles.

Cabin Space and Storage Design

Inside, the CLS is surprisingly accommodating for a four-door coupe. The rear seating area, optimized for two passengers, provides ample knee and shoulder room, while the sloped roofline only slightly reduces head clearance for taller occupants. The center tunnel layout reinforces the vehicle’s sporty stance but does not compromise comfort thanks to ergonomic seat positioning.

The 490-liter trunk offers enough space for medium-sized luggage, business gear, or weekend travel essentials. The split-folding rear seats (40:20:40) extend the usable space further, allowing long items like skis or golf bags to fit easily.

Practical Highlights:

• Spacious 490L trunk with split-folding flexibility
• Optimized 2,939 mm wheelbase for increased legroom
• Wide-opening doors and low loading sill
• Clever underfloor storage for smaller items
• Balanced coupe profile with daily practicality

Everyday Usability and Aerodynamic Benefits

While it projects a grand touring aesthetic, the CLS remains practical for everyday use. The automatic trunk lid opens hands-free, and the power-closing doors add a touch of refinement. Its turning circle of 11.6 meters ensures city maneuverability, and the parking assist cameras make tight spaces effortless to navigate.

The aerodynamically honed bodywork, including flush glass panels and active grille shutters, not only improves stability but also enhances fuel efficiency and cabin quietness. Combined with excellent visibility, refined ingress height, and efficient storage solutions, the 2021 CLS manages to blend style and sensibility seamlessly — a luxury coupe that remains practical in real-world use.

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Common Issues, Reliability, and Long-Term Durability

The 2021 Mercedes-Benz CLS maintains the brand’s reputation for exceptional engineering precision and long-term reliability. Built on the MRA platform, shared with the E-Class and S-Class, the CLS benefits from proven mechanical durability and continuous refinement of electronic systems. Mercedes has addressed many of the minor issues seen in earlier models, particularly in the areas of infotainment stability and electrical integration.

Mechanical Reliability and Engineering Integrity

The most significant improvement in the 2021 CLS lies in the adoption of the OM656 and M256 engine families — both designed for longevity and reduced mechanical stress. The inline-six M256 petrol engine, featuring the EQ Boost 48V mild-hybrid system, has been engineered with integrated starter-generator (ISG) technology, which reduces belt-driven components and minimizes wear. The OM656 diesel engine employs steel pistons and nanoslide cylinder coating, ensuring exceptional durability and efficiency over long distances.

Component	Expected Lifespan	Maintenance Interval	Notes
Engine (M256 / OM656)	350,000+ km	Oil change every 15,000–20,000 km	Designed for low-friction operation
Transmission (9G-Tronic)	300,000 km	Fluid change every 120,000 km	Adaptive gear shift logic
Suspension Bushings	180,000 km	Inspect every 60,000 km	Reinforced composite materials
Electrical System	10+ years	Software updates as required	Shielded harness reduces moisture faults
Paint & Body	15+ years	Periodic waxing recommended	Corrosion-resistant galvanized panels

Electrical and Infotainment Reliability

The latest generation MBUX infotainment system is more stable than earlier COMAND units, with faster processors and OTA update capability. Occasional issues such as Bluetooth pairing delays or voice recognition lag have been largely resolved through software revisions. The electrical layout features moisture-resistant harnesses and shielded connectors, reducing the likelihood of voltage fluctuations — a known weakness in previous CLS generations.

Reliability Highlights:

• EQ Boost hybrid system with simplified component design
• 9G-Tronic gearbox with robust adaptive programming
• High-strength body shell minimizing corrosion and noise intrusion
• Improved MBUX stability with OTA update support
• Long-life suspension and electrical components

Long-Term Durability and Owner Experience

Real-world feedback from CLS owners shows outstanding long-term satisfaction. Many report consistent engine smoothness and negligible performance degradation even after 200,000 km of use. The AIRMATIC air suspension has proven reliable with proper maintenance, and its components are designed for easy servicing.

Corrosion protection remains a key strength: Mercedes’ multi-layer paint application and galvanized steel structure offer resilience even in harsh climates. Regular updates through the Mercedes Me Connect platform ensure that both software and mechanical diagnostics remain current, extending component life.

Overall, the 2021 Mercedes-Benz CLS stands as a well-engineered, low-maintenance luxury coupe designed for endurance. It combines timeless mechanical strength with digital reliability — a balance few vehicles achieve this elegantly.

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Maintenance, Ownership Experience, and Service Intervals

The 2021 Mercedes-Benz CLS embodies the essence of luxury ownership — effortless maintenance, intelligent diagnostics, and long-term reliability. With extended service intervals, predictive maintenance monitoring, and an advanced ASSYST Plus system, the CLS ensures minimal downtime and consistent performance, even after years of use.

Maintenance Intervals and Digital Monitoring

Mercedes’ ASSYST Plus system continuously evaluates oil quality, fluid levels, and wear data, adjusting service intervals dynamically according to driving behavior. Under typical conditions, maintenance is required every 25,000–30,000 km or 2 years, whichever comes first — an impressive interval for a high-performance luxury coupe.

Maintenance Task	Recommended Interval	Notes
Engine Oil & Filter	Every 20,000–30,000 km	Synthetic oil for M256/OM656 engines
Brake Fluid	Every 2 years	Maintains hydraulic performance
Transmission Fluid (9G-Tronic)	Every 120,000 km	Prevents clutch wear and shifting lag
Air & Cabin Filters	Every 25,000 km	Ensures clean airflow and comfort
Coolant	Every 10 years / 200,000 km	Long-life formula with corrosion inhibitors
Software Updates	OTA / as required	Delivered automatically via MBUX system

The 9G-Tronic transmission and EQ Boost mild-hybrid system are nearly maintenance-free, requiring only routine inspections. The use of synthetic lubricants and self-regenerating Diesel Particulate Filters (DPF) minimizes workshop visits, further lowering total ownership costs.

Ownership Experience and Comfort of Use

Owning the CLS extends beyond mechanical reliability — it’s about the experience. Through Mercedes Me Connect, owners gain real-time access to vehicle diagnostics, service scheduling, and remote control functions (such as door locking or climate pre-conditioning). The system also provides reminders for upcoming maintenance and can communicate directly with authorized service centers to streamline appointments.

Ownership Highlights:

• ASSYST Plus adaptive maintenance tracking
• Mercedes Me Connect for digital vehicle management
• Extended service intervals reducing total cost of ownership
• Self-cleaning DPF and long-life fluids lowering maintenance effort
• Comprehensive service network ensuring global support

Warranty, ServiceCare, and Long-Term Value

The CLS comes with a 4-year / 80,000 km comprehensive warranty and an 8-year coverage for EQ Boost components. Mercedes’ ServiceCare Maintenance Plans offer prepaid packages that include labor, genuine parts, and roadside assistance, ensuring cost predictability and premium service quality.

The build quality, paint durability, and engine longevity of the 2021 CLS contribute to strong resale values, especially in markets that favor well-maintained Mercedes models. Its combination of low maintenance requirements, digital monitoring, and global service availability solidifies it as one of the most ownership-friendly vehicles in its class.

Ultimately, the 2021 Mercedes-Benz CLS redefines luxury maintenance — intelligent, efficient, and reassuringly simple. It’s a car designed not just for driving pleasure, but for long-term satisfaction and peace of mind.

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Frequently Asked Questions About the 2021 Mercedes-Benz CLS

What engine options are available for the 2021 Mercedes-Benz CLS?

The 2021 CLS offers three main powertrains: a 2.0-liter turbocharged four-cylinder, a 3.0-liter inline-six diesel, and the M256 3.0-liter inline-six petrol engine with EQ Boost. The petrol version features a 48V mild-hybrid system that assists acceleration and reduces fuel consumption. Power output ranges from 258 hp in the CLS 300 to 367 hp (+21 hp electric boost) in the CLS 450 4MATIC.

How fast is the 2021 Mercedes-Benz CLS?

Performance depends on the model. The flagship CLS 450 4MATIC accelerates from 0–100 km/h in just 4.8 seconds, thanks to the seamless torque delivery from the EQ Boost system and 9G-Tronic transmission. Even the diesel-powered CLS 400d offers strong mid-range power with 700 Nm of torque, ideal for long-distance comfort and motorway overtaking.

How fuel-efficient is the 2021 CLS in real-world driving?

The CLS 300 achieves around 7.2 L/100 km, while the CLS 450 EQ Boost averages 7.6 L/100 km under WLTP testing. Diesel versions can deliver 6.3 L/100 km, making them ideal for high-mileage drivers. The EQ Boost hybrid system supports coasting and regenerative braking, improving overall efficiency and reducing CO₂ output.

What is the average maintenance cost for the 2021 CLS?

Maintenance costs vary by region, but the CLS benefits from extended service intervals of up to 30,000 km or 2 years. Its ASSYST Plus system monitors oil, filters, and fluid levels automatically, notifying the driver when service is required. Regular upkeep includes engine oil, brake fluid, and filters, while the EQ Boost hybrid system requires no additional maintenance.

Does the 2021 CLS support Over-The-Air updates?

Yes, the 2021 CLS features Over-The-Air (OTA) functionality via the MBUX infotainment system. This allows for software and navigation map updates without visiting a dealership. OTA capability also ensures that driver assistance and EQ Boost software remain current, enhancing reliability and performance over time.

How reliable is the 2021 Mercedes-Benz CLS?

The CLS benefits from proven components shared with the E-Class and S-Class, including the M256 engine, 9G-Tronic gearbox, and AIRMATIC suspension. These systems have been extensively tested for endurance and reliability. Common user feedback highlights exceptional long-term performance, smooth ride quality, and minimal unscheduled repairs when maintained properly.

What safety features are standard in the 2021 CLS?

Standard features include Active Brake Assist, Attention Assist, Crosswind Assist, and multiple airbags. Optional upgrades from the Driver Assistance Package Plus add Active Steering Assist, PRE-SAFE® collision preparation, and Active Distance Assist DISTRONIC for semi-autonomous highway driving.

Does the 2021 Mercedes-Benz CLS have a hybrid or electric version?

While not a plug-in hybrid, the CLS 450 4MATIC includes a 48V mild-hybrid EQ Boost system, offering electric assistance during acceleration and coasting. This setup improves performance and efficiency without requiring external charging — a balanced solution between traditional and full-hybrid drivetrains.

How comfortable is the CLS for long-distance travel?

Exceptionally so. With its AIRMATIC air suspension, acoustic glass, and multi-contour seats offering heating, ventilation, and massage functions, the CLS excels in long-distance refinement. The NVH insulation ensures whisper-quiet cabin comfort, while ENERGIZING Comfort Control adjusts lighting, climate, and music for fatigue-free driving.

Is the 2021 Mercedes-Benz CLS worth buying?

Absolutely. It combines the luxury and technology of an S-Class with the sporty design of a coupe. The 2021 facelift improves efficiency, infotainment, and comfort, making the CLS one of the most refined and timeless models in Mercedes’ lineup. For those seeking elegance without sacrificing practicality, the CLS remains a top-tier choice.