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The Mercedes-Benz 450SEL 6.9 is the high-performance top-of-the-line version of the W116 model S-Class luxury saloon. It was built by Daimler-Benz in Stuttgart, Germany and based on the long-wheelbase version of the W116 chassis introduced in 1972. The model was generally referred to in the company's literature as the "6.9", to distinguish it from the regular 450SEL. It featured the largest engine of any non-American production car post WWII.[1][2][3][4]

Mercedes-Benz 450SEL 6.9
450SELI 0411.jpg
Body and chassis
ClassFull-size luxury car (F)
PlatformMercedes-Benz W116
Engine6.834 L M100 V8
Transmission3-speed automatic
Wheelbase2,960 mm (116.5 in)
Length5,060–5,335 mm (199.2–210.0 in)
Width1,870 mm (73.6 in)
Height1,430 mm (56.3 in)
Curb weight1,985 kg (4,376 lb)
PredecessorMercedes-Benz 300SEL 6.3
SuccessorMercedes-Benz 560 SEL (direct)
Mercedes-Benz S 600 (ideological)
Mercedes Benz S 63 AMG (spiritual)

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 (since 1985)—the top of range 560 SEL—continued the 6.9's self-levelling hydropneumatic suspension as an extra-cost option. Active Body Control is the current iteration of this innovation.



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 suspension.[5]

The benefit of this arrangement is progressive springing. The more the enclosed air in the suspension is compressed, the more difficult it is to compress; thus the suspension rate changes in proportion to the load.[5]

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. 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. 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.

Euro-spec 450SEL 6.9

The suspension system gave the 4200 pound (1900 kg) car the benefits of 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 a dry road surface 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 plantEdit

The engine was a cast iron V8 with single overhead camshafts operating sodium-filled valves 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. The 6.9 l (6834 cc or 417 in³) power plant was factory-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. A special version for Australia, based on the North American version, however without catalyst, was rated at 269 hp (198 kW) with 51 kpm (510 N·m) of torque.[6] 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. 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 performanceEdit

Top speed was factory-rated at 140 mph (225 km/h). Among the journalists that tested and reviewed the car 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.[7]

US exportsEdit

US market 450SEL 6.9

Of the 7,380 units built, 1,816 were officially sold in the US.

When the car was 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 6.9 was rather austere compared to the opulence in competitors like the Rolls-Royce or Cadillac. [5] 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, when the Rolls-Royce Silver Shadow sold for $43,200. [5] [8]

The 6.9's variable height suspension was illegal in the U.S. at the time so U.S. specification cars deleted the knob that allowed the driver to raise the car.[9]

The North American version was rated with 36 fewer horsepower and 45 fewer lb·ft torque (250 and 360, respectively), due to differing emission standards.[10]

US models also had extended "park bench" impact absorbing bumpers.

The US cars were fitted with four fixed round exposed lamps. 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. Separate glass windshields for headlights were illegal in the US after 1967, which is why the Citroën DS did not get them on US cars when it was restyled for 1968, and the VW Beetle and Vanagon/Kombi and Jaguar E-Type lost their headlight glass windshields at the same time.[11]


The dashboard of a Mercedes-Benz 450SEL 6.9

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.[citation needed] A total of 7,380 units were built by 1980, with only 1,816 officially sold in the US. 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.[citation needed]

Interior features (Pullman interior)Edit

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. 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 by 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.

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.

Being the top-of-the-line offering in its brand and model lineup, the 6.9 was rather indistinguishable from its W116 stablemates save for a modest "6.9" badge on the decklid and wider tires.[5] The badge could be deleted/ordered with option No. 261 i.e. omission of the displacement figure on the trunk lid at extra cost from the factory. 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.[5]

Cultural referencesEdit

  • The 6.9 featured prominently in a high-speed car chase in the film Ronin and was in all probability the actual car (with an overlaid sound track from a Ferrari 275 GTB) driven in Claude Lelouche's short film C'était un rendez-vous where it is driven through Paris at high speed with a camera mounted on the front bumper.
  • In David Lynch's 1996 film, Lost Highway, a Mercedes 6.9 is used as a major plot device, ultimately connecting all three main male characters of the movie. In one scene, the hood is opened to reveal an after-market modification, bringing the engine power to "1400 horsepower", according to one character. In another scene, the car is used to push a Ford Thunderbird off the road, despite the latter applying the brakes.[12][13][14]


Mercedes-Benz 450SEL 6.9[15]
Manufacturer Daimler-Benz AG
Class Five-passenger, four-door luxury sedan
Body Styles Four-door sedan
Predecessor 300SEL 6.3
Successor None
Shares components with Mercedes-Benz 600, Mercedes-Benz 300SEL 6.3, other Mercedes-Benz W116 sedans
Wheelbase: 116.5 in 2960 mm
Front track 59.9 in 1521 mm
Rear track 59.3 in 1505 mm
Overall length: 199.2 in 5060 mm
Overall length (US): 210 in 5335 mm
Width: 73.6 in 1870 mm
Curb weight: 4390 lb 1985 kg
Fuel tank capacity 25 US gal; 21 imp gal 95 L
Trunk (boot) capacity 18.2 ft³ 0.52 m³
Battery capacity 12 V, 88 A·h
Steering wheel turns 2.7 lock-to-lock
Turning circle 40 ft 12.1 m
Head Room - Front 38.6 in 980 mm
Leg Room - Front 41.7 in 1060 mm
Hip Room - Front 57.5 in 1460 mm
Shoulder Room - Front 55.1 in 1400 mm
Head Room - Rear 37.1 in 942 mm
Leg Room - Rear 38.1 in 967 mm
Hip Room - Rear 59.5 in 1510 mm
Shoulder Room - Rear 54.9 in 1394 mm
Engine V-8, Bosch fuel injection, electronic ignition, two single overhead camshafts, five main bearings
Net power @4250 rpm (World) 286 PS 210 kW
Net torque @3000 rpm (World) 405 lbf·ft 549 Nm
Net power @4200 rpm (Australia) 269 HP 198 kW
Net torque @2800 rpm (Australia) 376 lbf·ft 510 Nm
Compression ratio (World) 8.8:1
Net power @4000 rpm (North America) 250 hp 186 kW
Net torque @2500 rpm (North America) 360 lbf·ft 488 Nm
Compression ratio (North America) 8.0:1
Bore/stroke 4.21 × 3.74 in 107 × 95 mm
Displacement 417.1 in³ 6834 cc
Maximum engine speed 5300 rpm
Transmission: Three-speed automatic with torque converter
Rear axle ratio 2.65:1
Tires and wheels Michelin XWX 215/70VR14 steel-belted radial; 6.5Jx14 light alloy
Braking system Dual-circuit, power-assisted hydraulic, four-wheel disc brakes. Front discs ventilated.
Total swept brake area 456.5 in² 2945 cm²
Acceleration 0–60 mph: 7.1 seconds 0–97 km/h: 7.1 seconds
Top speed (World) 140 mph 225 km/h
Year World North America
1975 474 0
1976 1475 0
1977 1798 462
1978 1665 437
1979 1839 576
1980 129 317
1981 4 0
Total 7380 1816


Magazine test results:

  • 0–30 mph (48 km/h): 2.5 s[16]
  • 0–40 mph (64 km/h): 3.9 s[16]
  • 0–50 mph (80 km/h): 5.3 s[16]
  • 0–60 mph (97 km/h): 7.1 s[16]
  • 0–70 mph (113 km/h): 9.3 s[16]
  • 0–80 mph (129 km/h): 12.0 s[17]
  • 0–90 mph (145 km/h): 15.4 s[16][17]
  • 0–100 mph (161 km/h): 19.5 s[17]
  • 0–110 mph (177 km/h): 24.9 s[17]
  • 0–120 mph (193 km/h): 33.1 s[17]
  • 0–124.3 mph (200 km/h): 33.7 s[18]
  • 0–62.1 mph (100 km/h): 7.8 s[18]
  • Standing 14 mile (402 m): 15.4 s @ 90 mph (145 km/h)[17]
  • Standing 1 km (0.62 miles): 28.2 s @ 115 mph (185 km/h)[17]
  • Braking 70-0 mph: 207 ft (113–0 km/h: 63 m) (0.79g)[16]
  • Fuel economy, EPA mileage cycle: 10 miles per US gallon (23.5 L/100 km; 12.0 mpg‑imp) urban, 14 miles per US gallon (16.8 L/100 km; 16.8 mpg‑imp) highway[16]
  • Top speed: 147 mph (237 km/h)[18]


  1. ^ "V8 Week: 1979 Mercedes-Benz 450SEL 6.9". German Cars For Sale Blog. Retrieved 2016-07-16.
  2. ^ "Mercedes-Benz S-Class - 280S, 280SE, 280SEL, 300SD, 350SE, 350SEL, 450SE, 450SEL & 450SEL 6.9". W116. 2015-06-15. Retrieved 2016-07-16.
  3. ^ "In the lap of luxury: The Mercedes S-Class W116 | Classic Driver Magazine". 2013-07-11. Retrieved 2016-07-16.
  4. ^ "Mercedes-Benz S-Class - 280S, 280SE, 280SEL, 300SD, 350SE, 350SEL, 450SE, 450SEL & 450SEL 6.9". W116. 2015-06-15. Retrieved 2016-07-16.
  5. ^ a b c d e f David E. Davis Jr. (July 1977), Mercedes-Benz 450SEL 6.9 - Archived Road Test, Car and Driver, archived from the original on 2011-09-27
  6. ^ AUS Service Literature
  7. ^ "Brock Yates' 6.9 Evaluation, from 6.9 Promotional Literature from Mercedes-Benz". Retrieved 2016-07-16.
  8. ^ "Advertisement: Refinement of a Masterpiece". Black Enterprise. June 1977. Retrieved 10 April 2017.
  9. ^ "1978 Mercedes-Benz 6.9 Sedan". Significant Cars. Retrieved 10 April 2017.
  10. ^ Lieberman, Jonny (19 September 2007). "Mercedes-Benz 450SEL 6.9". Jalopnik. Retrieved 10 April 2017.
  11. ^ Angela Greiling Keane (28 March 2013). "Audi Wants to Change a 45-Year-Old U.S. Headlight Rule". BloombergBusinessweek. Retrieved 22 August 2016.
  12. ^ IMCDB
  13. ^ Motoring Con Brio
  14. ^ Mercedes in the Movies Archived 2012-03-22 at the Wayback Machine
  15. ^ Oswald, Werner (2003). Deutsche Autos 1945-1990, Band 4. Stuttgart: Motorbuch Verlag. pp. 80, 86. ISBN 3-613-02131-5.
  16. ^ a b c d e f g h "Car and Driver July 1977". Retrieved 28 July 2016.
  17. ^ a b c d e f g Autocar 24 March 1979
  18. ^ a b c Automobil Revue 29/1976 15. Juli 1976

External linksEdit