Mercedes-Benz W140


The Mercedes-Benz W140 is a series of flagship vehicles that were manufactured by the German automotive company Mercedes-Benz from 1991 to 1998. Mercedes-Benz unveiled the W140 S-Class at Geneva Motor Show in March 1991 with sales launch in April 1991 and North American launch in August 1991. The W140 represented the last of old school German engineering from Mercedes-Benz that leaned on overengineering principle, namely "engineer's car". As with each generation of S-Class, a plethora of innovations in technology, climate protection, and creature comfort was introduced. Those innovations later trickled down to smaller C-Class and E-Class models over time.
As with previous generations of S-Class, the W140 was available in two body styles along with two wheelbase lengths. The standard wheelbase, SE, and long wheelbase, SEL, along with coupé version, SEC, was renamed in 1993 as part of the corporate-wide nomenclature changes for 1994 model year onward, becoming S only regardless of wheelbase length or body style as well as fuel type. A TURBODIESEL label affixed to the right side of the trunk/boot lip was the only visual clue of its diesel engine. In 1996, the S-Class coupé was renamed again as CL-Class and split off to its own model range.
The W140 gained a notoriety for its substantial appearance with tall roof and larger side windows, described as "driving safe box", brick on wheels, moving shoe carton, etc. Emerging concerns for climate protection and the effect of global recessions in the early 1990s targeted the W140 as an ostentatious symbol of excess. A further notoriety for the W140 occurred when Diana, Princess of Wales died in a car crash, involving a S 280 model, in a Paris tunnel in 1997. The only survivor of the W140 sat in the front passenger seat.
The W140 series S-Class was superseded by the W220 S-Class sedan and C215 CL-Class coupé in 1998 after an eight-year production run.
Mercedes-Benz built 432,732 examples of the 140 series, comprising 406,710 sedans and 26,022 coupés.

History

The development on the W140 began in 1981, with official introduction originally set in September 1989. Several different design proposals were studied from 1982 until 1986, when a definitive design proposal by Olivier Boulay was selected on 9 December 1986. Several engineering prototypes were evaluated from early 1987, with the final exterior design locked in September 1987. The design patents were filed on 23 February 1988 in Germany and 23 August 1988 in the United States. The lead designer Bruno Sacco attributed Jaguar's XJ40 sedan and BMW's E32 7-Series as a major influence in W140 design. The initial exterior design proposal called for the two different cooling grille designs to denote the lower and upper model, similar to the idea of round and rectangle headlamps on the W123. Innovative metal-forming technology allowed the extension of the engine hood/bonnet to the front bumper, with the grille placed inside the extruded metal. The W140 became the second model after the R129 to have this extruded metal grille.
When BMW introduced a new 7-Series in 1986, a first post-war German passenger V12 engine, M70, was offered. This surprise announcement forced Mercedes-Benz to delay the introduction of the W140 by eighteen months to 1991. The delay allowed Mercedes-Benz to develop the new V12 engine and to rearrange the engine bay to accommodate the garguntan V12 engine along with upgrading the brake system. The final development prototypes were completed in June 1990, with pilot production models being built from June 1990 to January 1991.
The W140 is often known as the last Mercedes-Benz to be "overengineered" or "engineer's car", a trait which reportedly cost Mercedes-Benz more than $1 billion to develop. The project cost overruns and eighteen-month delay resulted in the departure of Wolfgang Peter, Mercedes-Benz' chief engineer. For the consumers, the price of a W140 was considerably 25 per cent higher than its predecessor, the W126, leading to slow sales during the recession of 1990-1994. Consequently, Mercedes-Benz shifted from "engineer's design" to "market-driven design" in the 1990s, resulting in the "lower quality" feel to the subsequent vehicles introduced in the late 1990s to 2000s, starting with the W210.
A stillborn V16 engine based on an elongated V12 engine meant for a hypothetical 800 SEL/S 800 was, again, developed in response to the purported rumour of BMW exploring a V16 engine and testing it in a 7-Series mule, named Goldfisch V16. Mercedes-Benz had a small fleet of 85 W140 prototypes with V16 engines. Due to the increasing concern for climate protection and fear of sending a wrong message to the public in the early 1990s, the V16 engine was quietly cancelled.
The updated W140 was unveiled at the 1994 Geneva Auto Salon and went on sale in April 1994.

Models

The three body types are carried over from the W126: four-door sedan/saloon in two wheelbase lengths and one two-door coupé. The model types are assigned as W140 for standard wheelbase, V140 for long wheelbase, and C140 for coupé. In 1996, S-Class coupé was renamed as CL-Class and spun off from S-Class. A longer Pullman version with 4140 mm wheelbase was introduced in 1995 with two engine choices. The S 600 Pullman could be ordered with armour package.
The Sultan of Brunei ordered eighteen S 73 T station wagons/estates with AMG-prepared M 297 7.3-litre V12 engines putting out 391 kW and 750 N⋅m to be built, with ten units delivered. The S 73 T had an S-Class coupé front end and the rear part of an S210 station wagon/estate installed.
A one-off custom-built S 500 lang Landaulet Popemobile was built for Pope John Paul II in 1997.

Features

Safety

The W140 S-Class introduced several safety innovations which have since become commonplace among many vehicles.
Some innovations for the W140 included:

Engines

A new generation of inline 6 and V8 petrol engines were developed with double-overhead camshafts, four valves per cylinder, and new variable valve timing. Mercedes-Benz's first-ever passenger V12 engine was introduced in 1991 in a response to BMW's 750i/750iL. Only 3.5-litre inline 6 diesel engine, OM 603.97x, was carried over from W126 and remained only engine in W140 model range with two valves per cylinder form until its replacement in 1996. The DOHC, four valves per cylinder, and variable valve timing helped increase the horsepower and torque figures without heavy fuel consumption penalty while reducing the emission. All petrol engines have catalysators during the entire W140 model run regardless of where they were sold.
The 3.0-litre 24-valve inline 6, M 104.98x, was first introduced in 300 SL-24 and 300 E-24, 300 CE-24, and 300 TE-24 in 1989. This engine, fitted to 300 SE/300 SEL, had a very short run in W140; it was replaced by an upgraded inline 6 engines introduced in 1993 with two displacements. The smaller 2.8-litre M 104.94x engine was fitted to 300 SE 2.8 then S 280. The larger 3.2-litre M 104.99x engine was fitted to 300 SE/300 SEL then S 320.
The M 119 V8 engines were available in 4.2-litre and 5.0-litre versions and remained unchanged during its entire model run. In 1994, AMG developed a 6.0-litre version with and in a very limited production for Japanese market. The S 500 AMG 6.0 and CL 500 AMG 6.0 were built from 1994 to 1999 per customer order. For 1993, the V8 engines were detuned for improved emission control.
The M 120 V12 engine was offered in 6.0 litres only for the entire model run. This engine developed 290–300 kW and 569–580 N⋅m of torque for the 6.0-litre version. The 300 kW version was available in Europe from 1991 to 1992 and in the United States for 1992 only. In 1993, the V12 was slightly detuned to 290 kW for lower emission control. An AMG-prepared 6.0-litre M 120 V12 with higher performance rating, 327 kW and 623 N⋅m, was not officially available for S-Class sedan/saloon as it was exclusive to CL-Class and SL-Class.
The 3.5-litre inline 6 diesel engine, OM 603.97x in 300 SD TURBODIESEL and S 350 TURBODIESEL was at last offered outside North American and Japanese markets for the first time. This engine was replaced in 1996 by all-new 24-valve OM 606.961 ERE engine. This engine was loosely derived from M 104 petrol engine with different crankshaft and cylinder head. The smaller engine fitted to S 300 TURBODIESEL put out 130 kW and 330 N⋅m. The fuel was delivered indirectly in the precombustion chamber before entering the combustion chamber.

Transmissions

W140 remains the only S-Class to have wider range of transmissions during its eight-year run. The transmission choices at the introduction was 5-speed manual and 4-speed 4G-Tronic automatic. A new 5-speed 5G-Tronic was introduced in 1994 for inline 6 petrol engines only. In September 1995, 5G-Tronic was updated with electronic control for more optimal shifting points based on the sensor readings and became the sole automatic transmission option for the entire model range from 1996 to 1998.
The models equipped with inline 6 petrol engines have 5-speed manual transmission as standard with either 4-speed or 5-speed automatic transmission as extra-cost options. In June 1996, both 4-speed and 5-speed automatic transmissions were replaced by 5-speed electronically controlled automatic transmission. The inline 6 diesel engines were never offered with manual transmissions, following the "tradition" with W116 and W126. S 300 TURBODIESEL, introduced in 1996, received the 5-speed electronically controlled automatic transmission.
The models with V8 and V12 engines were offered with 4-speed automatic transmission as standard until August 1995. On September 1995, the 4-speed automatic transmission was replaced by 5-speed electronically controlled automatic transmission.
4MATIC, the all-wheel-drive system introduced in W124, was never fitted to W140 S-Class. W140's successor, W220, became the first S-Class to have 4MATIC as extra-cost option.

Technical Data

The figures given for acceleration, top speed, and fuel consumption are combination of all types of transmission and three body types wherever applicable.

General

Workshop manuals