Mercedes-Benz W116

Mercedes-Benz W116
Overview
Manufacturer Mercedes-Benz
Production 19721980
Assembly Sindelfingen, West Germany
Barcelona, Venezuela (CKD)
Designer Friedrich Geiger (1969, 1970)[1]
Body and chassis
Class Full-size luxury car
Body style 4-door sedan
Layout FR layout
Related Mercedes-Benz W114
Mercedes-Benz R107
Mercedes-Benz W123
Powertrain
Engine 2.8L I6
3.5L V8
4.5L V8
6.9L V8
3.0L I5 turbodiesel
Transmission 3-speed automatic
4-speed automatic
4-speed manual
5-speed manual
Dimensions
Wheelbase 2,865 mm (112.8 in)
2,965 mm (116.7 in) (SEL)
Length 4,960 mm (195 in)
5,060 mm (199 in) (SEL)
5,220 mm (206 in) (SE US bumpers)
5,334 mm (210.0 in) (SEL US bumpers)
Width 1,870 mm (74 in)
Height 1,410 mm (56 in) & 1,430 mm (56 in)
Chronology
Predecessor Mercedes-Benz W108
Successor Mercedes-Benz W126

The Mercedes-Benz W116 is a series of flagship vehicles produced from September 1972[2] until 1979. The W116 automobiles were the first Mercedes-Benz models to be officially called S-Class, although earlier sedan models had already unofficially been designated with the letter 'S' - for Sonderklasse or "special class."

History

The 'new' S-class generation development began in 1966, which was only a year after the launch of the W108/09. This was the first Mercedes saloon to feature the brand new corporate styling theme which was to be continued until 1993 when the 190 was discontinued. The design, finalized in 1969 (frozen in 1970) was a dramatic leap forward, with more masculine lines that combined to create an elegant and sporty character. The basic design concept was actually inspired from the R107 SL-Class roadster, especially the front and rear lights.[1]

The car was presented in September 1972. The model range initially included two versions of the M110 engine (Straight-six with 2,746 cc displacement) - the 280S (using a Solex carburetor) and the 280SE (using Bosch D-Jetronic injection), plus the 350 SE, powered by the M116 engine (V8 with 3,499 cc displacement). Half a year later two new models powered by the M117 engine (V8 with 4,520 cc displacement) were added to the range - the 450SE and the 450SEL (with a 100 mm longer body).

The most notable W116 was the high-performance, limited-production 450 SEL 6.9, which was introduced in 1975, and became the first production car to use an electronic four-wheel multi-channel anti-lock braking system (ABS) as an option from 1978 on. This model boasted the largest engine installed in a post-war Mercedes-Benz up to that time, and also featured self-leveling hydropneumatic suspension.

The 300 SD sedan (USA and Canada only) had a turbocharged 3.0-litre I5 diesel engine developed from the C111 experimental vehicle.

The 450SEL was named the European Car of the Year in 1974.

Production totaled 473,035 units. The W116 was succeeded by the W126 S-Class in 1979. The W116 was sold throughout Europe, the Americas, Asia, the Middle East, Africa, and Australia.

Models

The entry level six cylinder 280S was the only model in the range to incorporate a carburetor.

In 1975, the W116 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.

Chassis code Model Years Model Engine No. built[3]
W116.02019731980280 S sedan 2.8 L M110 I6 122,848
W116.02419731980280 SE sedan 2.8 L M110 I6 150,593
W116.02519741980 280 SEL sedan 2.8 L M110 I6 7,032
W116.02819731980 350 SE sedan 3.5 L M116 V8 51,100
W116.02919731980 350 SEL sedan 3.5 L M116 V8 4,266
W116.032 19731980 450 SE sedan 4.5 L M117 V8 41,604
W116.033 19731980 450 SEL sedan 4.5 L M117 V8 59,578
W116.03619751980 450 SEL 6.9 6.9 L M100 V8 7,380
W116.12019781980 300 SD sedan 3.0 L OM617 I5 turbodiesel
(USA and Canada only)
28,634

450SEL 6.9

US-market Mercedes-Benz 450SEL 6.9

The high-performance 450SEL 6.9 version of the S-Class was built on its own assembly line by Daimler-Benz in Stuttgart, Germany and based on the long-wheelbase version of the W116 chassis. The model was generally referred to in the company's literature as the "6.9", to separate it from the regular 450SEL.

The 6.9 was first shown to the motoring press at the Geneva Auto Show in 1974, and produced between 1975 and 1981 in extremely limited numbers. It was billed as the flagship of the Mercedes-Benz car line, and the successor to Mercedes-Benz's original high-performance sedan, the 300SEL 6.3. The 6.9 also has the distinction of being among the first vehicles ever produced with optional electronically controlled anti-lock brakes, first introduced by Mercedes-Benz and Bosch in 1978. The 6.9's successor—the top of range 500 SEL—continued the 6.9's remarkable self-leveling hydropneumatic suspension as an extra-cost option.

Special features

The 6.9 was the first Mercedes-Benz to be fitted with the hydropneumatic self-levelling suspension system introduced by Citroën in 1954, unlike the 600 and 6.3 which employed air suspensions. Using a combination of fluid-filled struts and nitrogen-filled pressure vessels or "accumulators" in lieu of conventional shock absorbers and springs, the system was pressurized by a hydraulic pump driven by the engine's timing chain. Compared to the new Mercedes-Benz system, Citroën's was belt-driven, exactly like a conventional power steering pump; failure of the Citroën system thus might result in loss of suspension. Conversely, every unit of the 6.9 was shipped with hard rubber emergency dampers that served as temporary springs and allowed the car to be driven in the event of a hydraulic failure. The special hydraulic fluid required by the system was stored in a tank inside the engine compartment. Not only was the system totally self-adjusting, ride height could be altered by a dash-mounted push-pull knob under the speedometer that raised the car an additional two inches (50 mm) for increased ground clearance. The National Highway Traffic Safety Administration (NHTSA) made this feature illegal in the US market, but it could be enabled simply by removing a limiter at the tank-mounted control valve.

Rear view of US market 450SEL 6.9

The suspension system gave the 4200 pound (1900 kg) car the benefits of a both a smooth ride and handling that allowed it, in the words of automotive journalist David E. Davis, to be "tossed about like a Mini." The car also featured a model W3B 050 three-speed automatic transmission unique to the 6.9 and a standard ZF limited slip differential both for enhanced roadholding performance on dry pavement and enhanced traction in inclement weather.

Four-wheel disc brakes and four-wheel independent suspension were standard across the W116 model range.

M-100 power plant

The engine was a cast iron V8 with single overhead camshafts operating sodium-filled valves (as are found in piston-driven aircraft) against hardened valve seats on each aluminium alloy cylinder head. Each hand-built unit was bench-tested for 265 minutes, 40 of which were under full load. Bosch K-Jetronic electromechanical fuel injection was standard at a time when fuel-injected cars were uncommon. As in all Mercedes-Benz automobile engines, the crankshaft, connecting rods and pistons were forged instead of cast. In non-US trim, the 6.9 l (6,834 cc or 417 in³) power plant was conservatively rated at 286 hp (213 kW) with 405 lb·ft (549 N·m) of torque helping to compensate for the 2.65 to 1 final drive ratio necessary for sustained high-speed cruising. The North American version, introduced in 1977, was rated with 36 fewer horsepower and 45 fewer lb·ft (250 and 360, respectively), due to more stringent emissions control requirements. In the interest of both engine longevity as well as creating some extra space under the hood, a "dry sump" engine lubrication system was used. Dry sump lubrication was originally developed for use in race cars as a way to prevent foaming of the engine oil by the crankshaft, which in turn would create a serious drop in oil pressure. The system circulated twelve quarts of oil between the storage tank and the engine, as opposed to the usual four or five quarts found in V8s with a standard oil pan and oil pump. As a result, the engine itself had no dipstick for checking the oil level. Rather, the dipstick was attached to the inside of the tank's filler cap (accessible from the engine compartment) and the oil level was checked with the engine running and at operating temperature. The dry sump system also had the benefit of extending the oil change interval to 12,500 miles (20,000 km). This, along with hydraulic valve lifters which required no adjusting and special cylinder head gaskets which eliminated the need for periodic retorquing of the head bolts, made the 6.9 nearly maintenance-free for its first 50,000 miles (80,500 km). The 6.9 required little basic service other than coolant, minor tune-ups, oil changes, and replacement of the air, fuel, oil and power steering filters.

Race track performance

Top speed was factory-rated at 140 mph (225 km/h), but some journalists testing the car saw speeds approaching 150 mph (241 km/h). Among those journalists was Brock Yates. Yates was approached by the factory to write promotional literature about the 6.9. He agreed, but under the condition that he could list the car's faults as well as its positives. Daimler-Benz agreed in turn, and Yates was given a US-spec 6.9 to drive from Manhattan to the Road Atlanta grand prix race track in Georgia. There, Yates would drive the car in as-arrived condition at racing speeds for a full 40 laps or just over 100 miles (160 km). The only change made to the car upon its arrival at Road Atlanta was the necessary adjustment of tire pressure. Driving 40 laps was a difficult task even for a purpose-built race car, let alone a street-legal sedan designed and geared for high-speed Autobahn cruising. The 6.9 suffered no mechanical problems and averaged a very respectable 72 mph (116 km/h) throughout the test, completing it with little more than excess dust on the bodywork from the Michelin radial street tires on which the car was driven to Atlanta. Yates was so comfortable driving the 6.9 around the track that he reported having run at least one lap with the sunroof open and the radio on, but the high price of the car made him think better of such risky driving and he finished the test with the radio off and both hands on the wheel.[4]

In September 2013, a 1979 W116 300SD was campaigned in the 24 Hours of Lemons at Carolina Motorsports Park, where it completed 165 laps at an average speed of 54.8 MPH.[5] It won the highest prize of the event, the Index of Effluency. Other than mild issues relating to brake and tire wear, no mechanical issues were encountered. After numerous modifications to handling, the car was again run in February 2014 at Barber Motorsports park in Birmingham, AL. It placed 44th, but turned 281 laps at an average pace of 59.6 MPH. One of the key advantages of the 300SD is its exceptional fuel economy on track, where it burns just 2.5 GPH (Roughly 18MPG). In July of 2014 it placed first in class at Sebring. It is still active in the series.[6]

Price and interior features

The dashboard of a Mercedes-Benz 450SEL 6.9, US version.

All of this technology came at a very high price. At a time when the most expensive Cadillacs, the mid-sized Seville and full-sized Cadillac Fleetwood Series Seventy-Five limousine each listed for about US$16,000, the 6.9 listed for around $40,000, more than the Big Three but less than most Rolls-Royces. When the car was officially introduced into the North American market for the 1977 model year, the price was well past $40,000 and was $52,995 by the end of production. The only way to get a 6.9 in the US or Canada prior to 1977 was to import one through the grey market. Though the 6.9 was undeniably a luxury car, it was a rather austere one compared to the sheer opulence available in a Rolls-Royce or full-sized Cadillac. The interior was identical to that in the less expensive models except for the push-pull suspension control knob just under the speedometer, a low suspension pressure warning and height adjustment indicator lights in the instrument cluster, and wood trim finished in burled walnut veneer on the dash and console. The rest of the W116 lineup was trimmed in striated zebrano veneer.

The 6.9 lacked expected luxury touches such as power-adjustable outside mirrors or front seats, although a unique power rear seat, heated seats and even orthopedically designed front seats were options. Buyers outside North America could also opt for headlight wipers and washers and/or headlights with a special vacuum-operated linkage whose aim could be adjusted at the dash depending on vehicle load. There was also a new standard feature in 1976: most Mercedes-Benz automobiles that year were equipped with a sophisticated electronic climate control system developed for Chrysler Corporation for use in their top models. The system turned on the heater, air conditioner or both, depending on the thermostat's setting and ambient temperature, automatically maintaining whatever temperature the driver selected. The compressor was an American import as well, supplied by the Harrison division of General Motors.

Far more modern than the contemporary Cadillac, which still had a live rear axle, and both faster and larger inside than the either the Rolls-Royce or Cadillac, the 6.9 was indistinguishable from its W116 stablemates save for a modest "6.9" badge on the decklid and wider tires.[7] US models also had different bumper rubbers fitted to the "park bench" impact absorbing bumpers. As discreet as the badge was, it could be deleted/ordered with option 261 omission of the displacement figure on the trunk lid at extra cost for those who wanted to avoid attention either from drivers of other high-performance cars or from law enforcement. In the words of David E. Davis, the 6.9 was "a $50,000 exercise in going fast."

Still, for fans of the discontinued 6.3 or for those who simply had to have a car which Car and Driver proclaimed to be "the greatest Mercedes-Benz ever built," it seemed that money was no object. At its launch in 1975, the 450SEL 6.9 cost DM 69,930. In the last year of production, 1979, the car was available at a price of DM 81,247. Even though this was far from inexpensive, the courage of the Mercedes-Benz strategists in launching the car onto the market paid off. A total of 7,380 units were built by 1980, and most of these were exported to the USA. This volume figure looks rather small at first glance, but production figures tend to be significantly smaller in the top luxury segment where this model competes. Also, the 6.9 was not the only S-Class model, and was purchased by the rich, the famous, and the powerful despite the rising cost of gasoline brought on by the Arab oil embargo. Thus, the 7,380 total sales volume is quite respectable once the price and contemporary economic climate are taken into account.

Today

In a poll conducted by Britain's Classic & Sports Car magazine and printed in their April 1999 edition, the Mercedes-Benz 6.9 ranked fourth on their list of the "world's greatest saloons."[8] The May 2004 edition of another British publication, Mercedes Enthusiast magazine, ranked the 6.9 number fifteen on their all-time top twenty list of great Mercedes-Benz automobiles. Even with such accolades, a 6.9 is a reasonably priced collectible automobile despite its rarity. The online NADA Used Car Guide lists a top value of US$40,000. At present, the market for cars of this type is somewhat soft, and a prime example can be had for considerably less. As is often the case with older cars that contain exotic engineering and parts unique to that one model, however, running and maintenance costs for a 6.9 can quickly overshadow a low initial purchase price.

Notable versions

Noted owners included: Sir Bernard Ashley; James Hunt;[13]Sir Sean Connery John F. Kennedy, Jr.; Frank Sinatra

Production

Mercedes-Benz 450SEL 6.9[3]
ProductionWorldNorth America
19754740
197614750
19771798462
19781665437
19791839576
1980129317
198140
Total73801816

Technical data

Technical data Mercedes-Benz W116 [14] (Manufacturer's figures except where stated)