Decoding the Generations: A Deep Dive into the W126 Mercedes-Benz

For enthusiasts of classic luxury, the W126 Mercedes-Benz stands as an icon of automotive engineering and timeless design. Produced from 1979 to 1992, this generation of the S-Class is broadly divided into two distinct series: the first generation (Gen 1) and the second generation (Gen 2). While both share the fundamental W126 DNA, numerous updates and enhancements differentiate these two iterations. For the discerning W126 Mercedes aficionado, understanding these nuances is crucial. This guide aims to provide a comprehensive breakdown of the key differences between the 1st and 2nd Generation W126 Mercedes-Benz, ensuring clarity for enthusiasts and potential owners alike.

Exterior Styling: Spotting the Gen 1 and Gen 2 W126

The exterior of the W126 Mercedes underwent subtle yet significant changes between generations. Recognizing these differences allows for quick identification of a Gen 1 versus a Gen 2 model.

• Production Years: The most fundamental distinction lies in the production timeline. 1st Generation W126 Mercedes models were produced from 1981 to 1985. The 2nd Generation W126 Mercedes followed, manufactured from 1986 to 1991.

• Wheelbase Options: A key difference in body styles is the availability of longer wheelbase models (+L) in the 2nd Generation. This provided increased rear passenger legroom and further solidified the S-Class’s luxury sedan status.

• Bumper Design: The bumpers received a noticeable redesign. 1st Generation models feature a bumper design with distinct vents, while the 2nd Generation adopted a smoother, more integrated bumper style.

• Lower Plastic Moldings: The lower plastic moldings along the sides of the car also evolved. 1st Gen models sport ribbed moldings, whereas the 2nd Gen features flat, sleeker moldings, contributing to a more modern appearance.

• Headlights: Perhaps one of the most visually apparent changes is the headlight design. 1st Generation W126 Mercedes headlights are recessed, giving a slightly set-back appearance. In contrast, 2nd Generation headlights are flat and flush with the grille, often incorporating a plastic cover for a streamlined look.

• Headlight Wipers: Headlight wipers, a characteristic feature of Mercedes-Benz from this era, were optional on the 1st Generation but became standard equipment on the 2nd Generation, enhancing visibility in inclement weather.

• Wheels: The wheel styles are another telltale sign. 1st Generation models are often seen with “Bundt” wheels, a slotted aluminum design. The 2nd Generation transitioned to 15-hole or 16-hole alloy wheels, offering a more contemporary aesthetic.

• Mirrors: Heated mirrors became standard on the 2nd Generation W126 Mercedes, adding a touch of convenience, especially in colder climates. These mirrors were also often automatically heated based on temperature.

• Sunroof: The sunroof mechanism also saw an update. 1st Generation models were equipped with an electric sliding sunroof. The 2nd Generation upgraded this to a tilting and sliding electric sunroof, offering more ventilation options.

• Rust Proofing: Mercedes-Benz implemented improved rust-proofing measures starting around 1985, meaning later 1st Generation models and all 2nd Generation W126 Mercedes vehicles generally benefit from enhanced corrosion resistance.

• Water Heated Windshield: A feature exclusive to the 2nd Generation is the water-heated windshield with a thermostat. This system aids in quicker defrosting and demisting of the windshield.

• Dome Light Design: Even subtle details like the dome light design were refined. 2nd Generation models often incorporated a seatbelt warning light into the dome light assembly.

Image of the recessed headlight design characteristic of the 1st generation W126 Mercedes, highlighting the set-back appearance.

Interior Refinements: Cabin Comfort and Technology in the W126

The interior of the W126 Mercedes also received notable upgrades, focusing on comfort, luxury, and integrating new technologies.

• Seat Design: The seat upholstery patterns are a key interior differentiator. 1st Generation models feature a 7-pleated seat design. Later 2nd Generation models offered big-pleated leather seats as an option, enhancing the plushness of the cabin.

• Seat Motors: While both generations featured power seats, the internal seat motor design differed between the 1st and 2nd Generation W126 Mercedes.

• Airbags: Safety technology saw a significant advancement. Airbags were an option in the 1st Generation. In the 2nd Generation, a driver’s side airbag became standard, with a passenger side airbag available as an option, reflecting growing safety consciousness in automotive design.

• Underdash and Console Storage: Practical interior features were added in the 2nd Generation, including an under-dash plastic key holder and a roll-top console box. These were often standard on models equipped with a passenger-side airbag, but available as options otherwise.

• Door Panels: The materials used for door panels evolved. 1st Generation models and early 2nd Generation versions often used vinyl door panels. Later 2nd Generation models transitioned to leather door panels, elevating the interior’s luxurious feel.

• Seatbelts: Rear seatbelt design was updated around 1985, with the introduction of retractor seatbelts (RS seatbelts), improving convenience and ease of use for rear passengers.

• Steering Column Adjustment: An adjustable steering column became a standard feature, enhancing driver ergonomics and comfort in the 2nd Generation W126 Mercedes.

• Electric Headrests: Electric headrests became standard in the 2nd Generation, offering another layer of adjustability and comfort for front occupants.

Luxurious interior of a 2nd generation W126 Mercedes showcasing the optional big-pleated leather seats and updated console design.

Drivetrain and Mechanical Enhancements: Under the Hood of the W126

Significant mechanical and powertrain changes occurred between the W126 Mercedes generations, impacting performance and efficiency.

• Differential Subframe Mounting: The differential subframe mounting configuration was revised, potentially affecting ride quality and handling characteristics.

• Window Regulators: The design of the window regulators was also updated, likely for improved reliability and smoother operation.

• Fuel Injection Systems: Engine management systems saw advancements. 1st Generation models utilized a frequency valve in their fuel injection systems. The 2nd Generation transitioned to the more advanced EHA (Electro-Hydraulic Actuator) valve system, contributing to improved fuel efficiency and emissions.

• Engine Options: The engine lineup was significantly revamped. 1st Generation gasoline engines primarily consisted of 380 and 500 series engines. The 2nd Generation saw the introduction of the 300, 420, and 560 series engines, offering a broader range of power and displacement options. On the diesel front, 1st Generation models featured the OM617 engine, while the 2nd Generation utilized the more advanced OM603 diesel engine (in specific years like 1986-87 and 1990-91).

Braking and Suspension Upgrades: Performance and Safety

The braking and suspension systems of the W126 Mercedes were also refined for enhanced performance and safety.

• Brake Calipers and Discs: The braking system received a substantial upgrade. 2nd Generation models were equipped with larger brake calipers and larger 300mm brake discs compared to the 274mm discs of the 1st Generation. This resulted in improved braking performance and stopping power.

• Rear Hydraulic Leveling Suspension: Certain top-of-the-line 2nd Generation models, specifically the 560SEL, featured rear hydraulic leveling suspension. This system automatically maintained a consistent ride height, regardless of load, enhancing ride comfort and handling.

• Anti-lock Braking System (ABS): ABS was offered as an option in 1984 and became standard on all W126 Mercedes models from 1985 onwards, marking a significant step forward in vehicle safety. This means ABS was standard on most late 1st Generation and all 2nd Generation models.

Electrical and Electronic Advancements: Modernizing the W126

The electrical and electronic systems of the W126 Mercedes benefited from technological progress, adding convenience and features.

• Memory Seats: Memory seats, allowing drivers to save and recall their preferred seating positions, were an option in the 1st Generation but became a standard feature in the 2nd Generation, enhancing convenience for multiple drivers.

• Radio Aerial Adjustment Switch: For the 1991 model year only, the radio aerial adjustment switch was deleted, likely as a simplification measure.

• Traction Control: Traction control, a pioneering safety and handling technology for its time, became available in the US market in 1991, exclusively for the final year of the 2nd Generation W126 Mercedes.

• Third Brake Lamp: A high-mounted third brake lamp became a standard safety feature in the 2nd Generation, improving visibility and reducing the risk of rear-end collisions.

• Low Fluid Warning Lights: Low washer fluid and low engine oil cluster warning lights became standard in the 2nd Generation, providing drivers with timely alerts for essential fluid levels.

• Becker Radios: Different Becker radio models were used in the 1st and 2nd Generations, reflecting advancements in car audio technology.

• Climate Control Systems: The climate control systems were also updated between generations, potentially offering improved efficiency and functionality in the 2nd Generation W126 Mercedes. Recirculation mode in climate control became a standard feature.

• Headlight Switch Design: The design of the headlight switch was refined, with illuminated lettering for easier nighttime operation in the 2nd Generation.

• Blower Motor Transistor: A solid-state transistor for the blower motor was implemented, likely improving reliability and longevity compared to earlier systems.

Conclusion: Appreciating the Evolution of the W126 Mercedes-Benz

The transition from the 1st to the 2nd Generation W126 Mercedes-Benz represents a thoughtful evolution, incorporating advancements in technology, safety, comfort, and styling while retaining the core values of luxury and engineering excellence that define the S-Class. Whether you prefer the classic charm of the 1st Generation or the enhanced features of the 2nd Generation, the W126 Mercedes remains a highly desirable and iconic vehicle. Understanding these key differences allows enthusiasts and potential buyers to appreciate the nuances of each generation and make informed decisions when choosing their perfect W126 Mercedes.