The Mercedes-Benz W 116 is a series of flagship luxury sedans produced from September 1972 until 1980. The W 116 automobiles were the first Mercedes-Benz models to be officially called S-Class, although some earlier sedan models had already been designated unofficially with the letter S for "special class" (). The W 116 was selected as European Car of the Year in 1974.
History
New rear suspension
The W 116 is the first S-Class, to use the same engineering as the W 114/W 115, but used a larger, separate platform. The S-Class from 1965 and "Pagoda" SL from 1963 would be the last of the low-pivot swing axle and king pin/double wishbone front ends.
The W 114 and W 115 models from 1968 are the first post-war Mercedes-Benz production cars to use a new suspension design. The semi-trailing rear arm and ball-joint front end format first displayed in the W 114/W 115 would be used in all new Mercedes passenger car models until the development of the multi-link rear suspensions of the 1980s.
The W 116 has independent suspension and disk brakes on all four wheels.
New corporate styling theme
The W 116's development began in 1966, which was only a year after the launch of the W 108/W 109. This is the first Mercedes-Benz sedan to feature the brand-new corporate styling theme, which endured until 1997, when the W 140 was discontinued. The design, finalized in December 1969, was a dramatic leap forward, with an elegant and sporty character. The basic design concept continued the themes originally introduced on the R 107 SL-Class roadster, especially the front and rear lights. As with the SL, the W 116 received the ridged lamp covers which keeps dirt accumulation at bay; this was to remain a Mercedes-Benz design theme into the 21st century. The W 116 was Friedrich Geiger's last design for Mercedes-Benz; his career had started with the Mercedes-Benz 500K in 1933.
1972: 2.8 L 6-cylinder and 3.5 L V8 engines
The W 116 was presented in September 1972. The model range initially included two versions of the M 110 engine (straight-six with 2746 cc displacement) — the 280 S (using a Solex carburetor) and the 280 SE (using Bosch D-Jetronic injection), plus the 350 SE, powered by the M 116 engine (V8 with 3499 cc displacement). After the 1973 oil crisis, a long-wheelbase 280 SEL was added to the model range.
1973: 4.5 L V8 engine
The larger 4.5-litre M 117 V8 engines were developed in response to US emission regulations and initially fitted to the 350 SL and 350 SLC for the US market in 1972, which were renamed as the 450 SL and 450 SLC in 1973. Mercedes-Benz introduced the 450 SE and 450 SEL for both US and international markets in 1973. The 4.5-litre models were available with three-speed automatic gearboxes only, while the models with smaller 3.5-litre V8 engine could be ordered with a four-speed manual gearbox. The 450 SE and 450 SEL received a plusher interior, with velour or leather seats rather than the checkered cloth of the lesser models. The door cards had the velour or leather inserts.Stjerna, p. 42
The 4.5-litre M 117 V8 engines had in most European and international markets, for the US market, and for Swedish and Australian markets. The 450 models received a plusher interior as well, with velour or leather seats rather than the checkered cloth of the lesser models. The door cards were also of a different design, with pads being pulled up around the windows.Stjerna, p. 42
1975: 6.8 L V8 engine
The most notable W 116 model was the high-performance 450 SEL 6.9, which was introduced in 1975. This model boasted the largest engine installed in a post-war Mercedes-Benz (and any non-American production automobile) up to that time, and it also featured self-leveling hydropneumatic suspension.
1978: 3.0 L 5-cylinder turbocharged diesel engine
Exclusive to the North American and Japanese markets was the 300 SD TURBO DIESEL, the world's first passenger car with a turbocharged diesel engine, which was introduced in 1978. No 300 SD TURBO DIESEL model was offered in Europe (where diesel engines were well-received and had tax advantages) until 1991, when the W 140 300 SD was finally introduced in Europe and international markets.
Production data
The 450 SE was named the European Car of the Year in 1974, even though the W 116 range was first introduced at the Paris Motor Show in the fall of 1972.Stjerna, p. 39
Production totaled 473,035 units. The W 116 was succeeded by the W 126 S-Class in 1979. The W 116 was sold throughout Europe, the Americas, Asia, the Middle East, Africa, and Australia.
Fuel injection
In 1975, the W 116 was upgraded with a new fuel injection system to comply with revised exhaust emission standards in European markets. A slight power reduction was a result of this update. In 1978, a series of engine upgrades restored original performance levels with new fuel injection systems. The D-Jetronic fuel injection system fitted to the early 280 SE (1973–1974) had computers and MAP sensor that are prone to failure after more than 20 years of use. From 1975 onward they used the K-Jetronic mechanical fuel injection system, a less complicated system that proved to be much more reliable in the long run with injectors costing significantly less than those used on the D-Jetronic system. The W 116 equipped with the K-Jetronic system used a cast-iron fuel distributor which can be prone to rust over time if moisture or water is present in the fuel. This was changed to an alloy fuel distributor in the following model W 126 and is not subject to corrosion.
Hydropneumatic suspension
W 116 was the first model from Mercedes-Benz to feature the hydropneumatic suspension system. While the principle is similar to Citroën's, Mercedes-Benz made some changes. The hydraulic pump was driven by the timing chain instead of a rubber belt for more reliability (Citroën's system would lead to loss of hydraulic power if the belt failed). Mercedes-Benz utilised the hard rubber dampers as temporary dampers in event of hydraulic failure. The height adjustment had a smaller range of height as compared to Citroën (40 mm versus 50 mm). Unlike Citroën, the car did not “sink” to the ground after shutting off the engine, and the driver did not have to wait for the hydraulic power to spool up and lift the car to the operating height.
The full hydropneumatic suspension system was fitted to the 450 SEL 6.9 as standard. In 1977, the self-levelling rear suspension system was offered for 450 SEL as an extra cost option outside the North American market.
North American sales
North America was a key market for the W 116. The model range for the U.S. market for 1973 was 450 SE and 450 SEL. Initially both models were unique to the US market, carrying on the tradition of the 4.5 litre W 108/W 109 versions they replaced (and would become available in Europe only in early 1973). For 1975, the 280 S was launched as a response to the 1973 oil crisis. For 1977, the 280 S and 450 SE were dropped due to slow sales and replaced with the 280 SE. The 6.9 was added for 1978 with the MSRP of $38,230 and continued to be sold until 1980.
Malaise era
Due to the series of new federal safety and emission regulations in the 1970s, the W 116 were described by journalists as if a "beautiful car was beaten with the malaise ugly stick." Furthermore, the performance was being continuously hampered by the increasingly stringent emission control and fuel economy legislation. Upon launch, the M 117 engine for the US market developed a SAE net rating of at 4750 rpm and at 3000 rpm for a car with curb weight of (450 SEL - ). In the final 1980 model year, the 450 SEL was producing at 4200 rpm and at 2500 rpm, weighing (international model at 5000 rpm, at 3250 rpm, ).
300 SD Turbodiesel
The 300 SD "TURBO DIESEL", the world's first passenger car with a turbocharged diesel engine, was launched in the United States and Canada in 1978. It had a 3.0-litre turbocharged inline-five diesel engine developed from the C111 experimental vehicle. The 300 SD became a best seller and helped considerably raise Mercedes-Benz's Corporate Average Fuel Economy (CAFE). Mercedes-Benz would make S-Class models with the turbocharged diesel engines exclusively for the North American and Japanese markets until 1992.
450 SEL 6.9
The high-performance 450 SEL 6.9 version of the S-Class was built on its own assembly line by Daimler-Benz in Sindelfingen, Germany and based on the long-wheelbase version of the W 116 chassis. The model was generally referred to in the company's literature as the "450 SEL 6.9" but simply "6.9" for the US market. Despite the model designation, the actual engine displacement is 6.8 litres.
The 450 SEL 6.9 was first shown to the motoring press at the Geneva Auto Show in 1974 and produced between 1975 and 1980. It was billed as the flagship of the Mercedes-Benz car line and the successor to Mercedes-Benz's original high-performance sedan, the 300 SEL 6.3.
Technical data