“Only once in a lifetime does one encounter this rare breed…..”
The Mercedes-Benz 450 SEL 6.9 saloon traveled with tremendous verve and élan. The 6.9 is an extremely high performance version of the W116 S-Class. It was manufactured from 1975-1981. The 450 SEL 6.9 was built on the long wheelbase W116 platform. This was the flagship of the Mercedes Benz model line-up.
The 6.9 was built at an extremely restricted pace. It was first introduced at the Geneva Auto Show in 1974. The 450 SEL 6.9 was a showcase of Mercedes-Benz technology for the day, such as being among the first vehicles ever produced with optional electrically controlled Anti-lock Braking Systems which were first introduced by Mercedes Benz and Bosch in 1978.
The 450 SEL 6.9 utilized a sophisticated self-leveling hydropneumatic suspension. The 6.9 pioneered high performance in the luxury saloon class. A total of 7,380 units were built by 1980 and most of these were exported to the USA. Many automobile journalist rate the Mercedes-Benz 450 SEL 6.9 as the greatest Mercedes-Benz ever built….I totally agree.
The impressive M100 power plant with 6.9 litre displacement (417 CID) was made from cast iron, a V8 configuration with single overhead camshafts. It used sodium-filled valves (the kind found in piston-driven aircraft) against hardened valve seats on each aluminium alloy cylinder head. This engine was built by hand and bench tested for 265 minutes, 40 of which under full load.
The crankshaft, connecting rods and pistons were forged rather than cast. This magnificent engine produced 286 hp with 405 lb-ft of torque with a top speed of 145-150mph. A Bosch K-Jetronic electromechanical fuel injection was used, which at the time was uncommon, the carburetor was king with every car manufacturer.
Mercedes-Benz utilized a Dry Sump engine lubrication system which required twelve quarts of oil. This type of lubrication was developed for race cars to prevent engine foaming to eliminate a serious drop in oil pressure. Dry Sump circulated twelve quarts of oil between the storage tank and engine. There was no engine dipstick for checking the oil level. Instead, the dipstick was mounted into the inside of the tank’s filler cap under the bonnet. The oil was checked while the engine was running at operating temperatures.
This high performance engine was virtually maintenance free. Hydraulic valve lifters required no adjusting and special head gaskets eliminated the need for the head bolts to be re-torqued. For the first 50,000 miles the car was nearly maintenance free. The 6.9 required little basic service other than coolant, minor tune-ups, oil changes, and replacement of air, fuel, oil and power steering filters. The 450 SEL 6.9 had the benefit of oil changes at 12,500 mile intervals.
The Mercedes-Benz 450 SEL 6.9’s hydropneumatic leveling system used a combination of fluid-filled struts and nitrogen-filled pressure accumulators instead of shock absorbers and sprigs. The system was operated by a hydraulic pump driven buy the engine timing chain. In case hydraulic failure, hard rubber dampers were shipped with each car that served as temporary springs which allowed the car to be driven until serviced. A special hydraulic fluid required by the system was stored In a tank in the engine bay.
The system was fully automatic but at the twist of a dash-mounted knob, the suspension could be raised an additional two inches for ground clearance. The National Highway Traffic Safety Administration (NHTSA) was not pleased, therefore, a tank mounted limiter was installed for the US market. (sh-h-h-h…the limiter could be removed to enable the system again!). The 450 SEL 6.9 used a four-wheel independent suspension and four-wheel disc brakes. It was built on the long wheelbase W116 platform.
The Mercedes-Benz 450 SEL 6.9 ranked fourth on their list of the world’s greatest saloons according to Britain’s “Classic & Sports Car” Magazine as of the April 1999 edition. In May of 2004 another British publication “Mercedes Enthusiast” Magazine ranked the 450 SEL 6.9 as number fifteen on their list of all-time top twenty list of great Mercedes-Benz automobiles. It is still regarded as highly collectible especially since it is such a rare offering.
The Mercedes-Benz 450 SEL 6.9 saloon’s prices started at $40,000 when the most expensive Cadillac Seville and Fleetwood Seventy-five limousine were priced around $16,000. By the time it reached the North American market for the 1977 model year, the price had increased to $52,995. This fire-breathing performance saloon has earned its place in automotive history as one of the most impressive and satisfying performers. The style of the 450 SEL 6.9 has been “mocked” by many manufacturers, but remember….Mercedes-Benz was the purveyor of performance, safety, and longevity. If you are looking for a classic car as an investment, I highly recommend the Mercedes Benz 450 SEL 6.9 saloon. My favorite color was the dark blue which made the car look even larger than it was.