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The Best of the Best: W116 S-Class 1973-1980
The W116 – the first S-Class – was the most technically advanced and safest luxury car of its era. Part III of a concise reference designed to help you choose a modern-classic Mercedes-Benz.
With the oil crises and pollution concerns, the 1970s defined an era of turbulence in the automotive industry that spared few upscale manufacturers. In this uncertain economic climate, Mercedes-Benz launched the W116 with high expectations from the public: it replaced the popular and robust W108 and W109 series.
The W116 is one of the most polarizing Mercedes-Benz series ever produced: W108 owners generally regard it as the car that solved the safety and environmental issues faced by early-1970s cars while others seem to prefer the more-evolved W126 that came after.
In response to the decade’s constantly changing government requirements, Mercedes was forced to use the W116 as a rolling test-bed for changing engine specifications, suspension tuning and, particularly, emissions technology, to adapt to changing U.S. emissions requirements.
Examples of these adaptations include the catalytic converter (1975 U.S. models), automatic climate control (1976, all models), the four-wheel selective leveling system (1976 6.9), the turbodiesel engine (1978) and K-Jetronic fuel injection (1976, all gasoline V-8 models). The darkest days of the model are exemplified by the 1975 and ’76 280S, which relied on a low-compression version of the M110 twin-cam six to generate 120 horsepower while returning a paltry 12 mpg at any speed above 70 mph.
But even cars like the 280S have found a niche today; many W116 fans are new to classic-Mercedes-Benz ownership. They often approach the W116 with fresh eyes that find the model to be charming and elegant in comparison with modern cars.
In the end, the W116 was given a new lease on life with the introduction of the endearing 300SD. The turbodiesel era of Mercedes automobiles had finally arrived; as a result, most of the W116s available today are diesels. But don’t worry. There are still plenty examples of the 280SE, 450SE and SEL available – even the 280S – for you to choose.
The 450SEL 6.9 was the top W116 model, offering unmatched luxury and power with a wheelbase extended 4 inches, a hydropneumatic suspension system with level control and a 6.9-liter V-8 engine. All W116 models shared restrained styling, generous interior space, a comfortable ride and industry-leading active and passive safety features, including the first production ABS system, co-developed with the Robert Bosch Company. Inside, a padded dashboard, deformable switches and a padded steering wheel provide advanced crash protection.
Background
Initial W116 models, including the 280S and SE and the 350SE were introduced in Europe in September 1972 for the 1973 model year; there never was a 1972 version. The predecessor W108 was phased out at the same time, a rare instance of a model-year gap. An early U.S. road-test model was built for Road & Track magazine in February 1973. By April 1974, the 450SE and SEL, 350SE and SEL and 280SEL had been introduced in Europe. The only models reaching the United States were the 450SE and SEL. The rest were destined for Europe until 1975, when the 280S was introduced in America.
In 1976, all V-8 models were updated with hydraulic valve tappets and K-Jetronic injection. The automatic climate-control system that Mercedes-Benz adapted from Chrysler was also standardized on U.S. models. This system has somewhat soiled the reputation of the 1976 and later W116s because it is difficult to repair.
The 450SEL 6.9, usually referred to simply as the “6.9” was also introduced as a 1976 variant in Europe; an American version followed in 1977. The 280S was replaced in 1977 by the stronger, faster 280SE (the United States never received a long-wheelbase version). In 1978, interest in the model was revived by the new 300SD – not as fast as a 450SEL – but still capable of 25-30 mpg. Production of this model continued into August 1980 with nearly 29,000 units produced.
The majority of W116s were phased out in Europe during the 1979 model year, but American market production continued into 1980.
Few if any major model changes occurred during the life of the W116. One huge change included the 1974 model year update (implemented in summer 1973) to larger bumpers to meet (then) recently instituted federal standards that required vehicles to withstand up to five-mph collisions without damage to lights, safety equipment or engines. The next major update occurred in 1976 with engine and climate-control changes.
Today, the W116 has found a well-deserved niche with enthusiasts who are new to classic Mercedes-Benz ownership. Bruno Sacco’s angular design appeals to the eye of a younger generation that appreciates the build quality and hipness of these cars – even when they sometimes don’t fully understand them. The 6.9 and 300SD have cult followings; the 6.9 in particular has begun to earn an especially enthusiastic reception in the last few years.
One of the company’s futuristic C111 record cars – key players in the development of the turbocharged diesel engine – poses proudly with its progeny, a 300SD Turbodiesel. The first S-Class with diesel power, the 300SD Turbodiesel was manufactured solely for the American and Canadian markets.
Reasons to buy a W116
Mechanical:
Consistent build quality, even on 1975-76 emissions-era cars
Mechanical robustness
Long driveline and suspension life
Structural:
Chassis can absorb a 40-mph impact without cabin intrusion
Comfortable interiors allow for extended trips
Personal:
Indie cred… if that sort of thing matters to you
Attractive styling, although this is subjective
Because you already own a W108/109 and a W126
Increasing interest from the collector-car community
Easily available service literature and mechanical-parts supply
Cheaper to purchase and service than a W108 or W109
The W116 300SD is an amazing car
Reasons not to buy a W116
Mechanical:
Poor fuel economy on gasoline models
Emissions headaches on 1975-76 U.S. market examples
Automatic climate-control systems are challenging to repair
Interior:
Difficulty finding interior and exterior parts
Personal:
Not as developed as the W126 that replaced it
Difficult sellers with unrealistic expectations
Checkpoints
Mechanical:
Front and rear glass seals often need replacement
Transmission leaks at the front seal
Driveshaft flex discs, engine mounts, rubber driveline parts
Leaking steering gear boxes
Play and noise in steering column means bad steering coupler
On 6.9s, test-drive to check hydraulic suspension for leaks and bouncing. Rebuilding a 6.9 hydraulic suspension is expensive
Worn front control-arm bushings, ball joints, steering linkages and upper control arms require replacement
Rear subframe bushings and rear control arms worn/rusty
Engines, whether M110, M116, M117 or OM617, are fairly sturdy and long-lived; V-8s may need timing chains and upper chain rails. The 6-cylinder engines may require a gasket between the cylinder head and camshaft-carrier bearing box. With the exception of
V-8 engines after 1975, all engines require regular valve-lash adjustment. Oil consumption should be assessed; valve guides commonly wear on gasoline engines
Structural:
Trunk wells often rust due to water collection
Floor pans rust, especially in areas low enough to collect water
Rust can permeate several other areas: at extremities of firewall, around the fuse box; sunroof tray (if sunroof-equipped); door bottoms; rocker panels (common in coastal or rust-belt cars); shock towers; under brake booster and climate-control servo on cars that have not been cleaned or garaged; in the cowl under cowl-vent grille due to drainage issues
Interior:
Interior panels, such as door panels, roof rail panels, center console, dash, etc., are prone to fading and cracking. These are not available new and used parts are difficult to source
Automatic climate-control systems usually need some kind of repair; servos are still available new, as are vacuum actuators
Woodwork is often lackluster, and refinishing is a challenge; it’s difficult to remove the wood from the car
If front/rear seats look deflated, excelsior pads are deteriorated – typical on early W116s – replacements cost over $3,000
Personal:
Look for a seller with realistic price expectations
The bottom line
The W116 is slowly gaining recognition. While these cars often require a good amount of work to get in order again, a sorted model can be a delight to drive. And the 280S – with its catalytic converter and Solex carburetor – can still be a fun car to own and drive regularly. Like all classic Mercedes-Benz vehicles, these are usable cars with excellent braking and handling; driving doesn’t feel like a chore.
While these fine automobiles are outstanding examples of intrinsic value, their commercial values don’t yet reflect the respect the cars deserve: This makes them a difficult sell for a profiteer. But a star-struck buyer will appreciate that the W116 is still one of the best-kept secrets in the world of classic Mercedes-Benz cars.
Introduced in September 1972, the W116 was the first Mercedes-Benz to be badged as an S-Class. The all-new vehicle was designed with an unprecedented level of safety, incorporating a rigid passenger safety cell with stiffened roof-frame structure, high-strength roof and door pillars and reinforced doors. Stylistic markers include large horizontal headlights, clearly visible indicator lights on front and side, ribbed taillights and bow-shaped door handles.
W116 Model Chronology
1972 September • 280S, 280SE, 350SE introduced
1973 March • 450SE, 450SEL (100mm longer wheelbase) introduced
1973 November • 350SEL introduced
1974 April • 280SEL introduced
1975 May • 450SEL 6.9 introduced as a successor to the 300SEL 6.3
1975 November - February 1976
• Improvements to fuel-injection system to meet more stringent emissions regulations on 2.8-, 3.5-, and 4.5-liter engines (Bosch K-Jetronic replaced D-Jetronic). Transistorized, breakerless ignition system introduced
1978 May •
The 300SD (3-liter, 5-cylinder turbodiesel) is produced exclusively for the United States and Canada to offer a luxury sedan with high fuel efficiency to meet “Corporate Average Fuel Economy” (CAFE) standards
1978 September •
Anti-lock brake system (ABS) introduced exclusively on the W116
1979 September • W126 model introduced
1980 April - September
• W116 production phased out according to model. Final W116 off the assembly line was a 300SD
W116 Sedan U.S. Product Specifications
450SE
Years: 1973-1975; Chassis: 116.032; Engine; 117.983;
Power: 1973: 190; 1974: Fed 190, Cal 180; 1975: 180; \
Torque: 1973: 240; 1974: Fed 240, Cal 232; 1975: 220.
Year: 1976 Chassis 117.986; Power: 180; Torque: 220
Total Produced: 41,604
450SEL
Years: 1973-1975; Chassis: 116.033; Engine: 117.983;
Power: 1973: 190; 1974: Fed 190 Cal 180
Torque: 1973: 240; 1974: Fed 240; Cal 232
Power: 1975: 180
Torque: 1975: 220
450SEL
Years: 1976-1979; Chassis: 117.986
Power: 1976-1979 180; Torque: 220
Power: 1980 160; Torque: 230
Global Total Production: 59,578
280S
Years: 1975-1976: Chassis:116.020 Engine: 110.922
Power: 120; Torque: 143; Global production: 122,848
280SE
Years: 1977-1979; Chassis: 116.024; Engine: 110.985
Power: Fed 142, Cal 137; Torque: Fed 149, Cal 142
280SE
Years: 1980; Chassis: 116.024; Engine: 110.985
Power: 140 Torque: 145
Global Production: 150,593
450SEL 6.9
Years: 1977-1979; Chassis: 116.036; Engine: 100.985
Power: 250; Torque: 360
Global Production 7,380 (US: 1,816)
300SD Turbo
YearsL 1979-1980; Chassis: 116.120; Engine: 617.950
Power: 1979: 110; 1980 120
Torque 1979: 168; 1980 170
Global Production: 28,634
Footnotes: During a decade when unleaded fuel and stricter pollution regulations strangled performance and economy, horsepower and torque ratings varied according to U.S. and California emissions controls. California law was most stringent, leading manufacturers to build separate California models.