The 1991 W140 S-Class was a technological tour de force, and possibly the finest car Mercedes-Benz ever made. Its arrival was also painfully mistimed. We remember the Uber-Benz on the thirtieth anniversary of its launch.
The arrival of a new Mercedes-Benz S-Class was always a seminal event for the automotive industry. It often heralded the introduction of new technology and safety features that would subsequently be adopted by other Mercedes-Benz models and, eventually, by its lesser competitors.
The 1959 W111 predecessor to the S-Class was the first car to feature a rigid passenger safety cell with front and rear crumple zones, to slow the deceleration that occurs in a high-speed impact and dissipate the kinetic energy released(1). In 1978, the W116 S-Class was the first car in the world to feature electronically controlled anti-lock brakes. The 1979 W126 S-Class introduced seat belt pre-tensioners, to restrain passengers in the event of an impact. This innovation was followed in 1981 by a driver’s side airbag, intended to work in concert with the seat belts(2) as part of the company’s Supplemental Restraint System (SRS).
The W140 S-Class was the replacement for the highly regarded and successful 1979 W126 model, which sold a total of 818,063 cars during its twelve-year production life. The design of the W126 had begun in the midst of the 1973 Middle East Oil Crisis and the anticipation of increasingly stringent US auto emissions standards, so fuel efficiency and low emissions were a priority from the beginning.
This resulted in a notably clean and elegant aerodynamic profile (with a Cd of 0.36) with limited and subtle decorative embellishment. The W126 was an understated car, even in long-wheelbase 560SEL form. That was exactly right for its intended customer base, who wished to travel in great comfort but relative anonymity. By any standards, the W126 would be a hard act to follow.
The driving force behind the W140 was Werner Niefer, who was chairman of the company’s board of management from 1989 to 1993, having sat on the board since 1987. It was Niefer who insisted that the company’s new flagship should look as impressive and imposing as possible, to be a visual metaphor for the peerless technology it contained and take its rightful place as the world’s best car.
Even in the critical North American market, where larger cars were the norm, the W140 must stand out as special, he insisted. To this end, all the development work took place on the standard LWB car, and the SWB version was a very late addition to the programme, sanctioned by Niefer with considerable reluctance.
The W140 was something of a shock when, after eight years in development, it was presented to the public at the Geneva Salon in March 1991. It was first revealed at a party in Geneva’s Noga Hilton Hotel ballroom, when a huge wooden container covering it was hoisted up into the ceiling. The journalists and industry watchers present clapped politely, but immediately began to discuss the social and environmental acceptability of such an apparent behemoth.
Mercedes-Benz’s marketing people explained somewhat unconvincingly that the car was finally catching up with the growth in size of its occupants over the preceding decades, but the doubts hardened. One German motoring magazine, Auto Motor und Sport, headlined its feature on the new S-Class “Sternegrog” or Star-Sized.
While still a commendably clean shape, it appeared to be a much bigger and bulkier car than its predecessor, which looked almost svelte by comparison. Appearances were deceptive, however: the SWB model was just 93mm (3¾”) longer, 66mm (2 ½”) wider and 49mm (2”) taller than its predecessor. The difference in length between the LWB models was even less(3), just 53mm (2”). One area where the two cars differed more markedly was their weight: the W140 SWB weighed from 1,880kg (4,145lbs), a hefty 360kg (792lbs) more than the W126.
Many might be surprised by the relatively minor differences in dimensions. The reason for the W140’s perceived greater bulk may be its overly deep side glass, which makes the cabin look much larger, and its smooth flanks, unadorned by any decoration other than the lower bodyside cladding. In any event, it makes the W126 appear to be a masterful design in the way it conceals its bulk.
There is an interesting anecdote concerning the height of the W140 to be found in a 2004 book(4) titled ‘The Challenge: Accelerating the Mercedes-Benz Brand’: Wolfgang Peter, Mercedes-Benz chief engineer, and car line manager Rudolf Hornig were both 190cm (6’3”) tall. Bruno Sacco, head of design, had originally envisaged a low and sleek car, inspired in part by Jaguar’s XJ saloon, but in 1987 when his tall colleagues sat in the mocked-up interior, they found themselves with insufficient headroom.
The mock-up’s adjustable roof was raised until both men were comfortable and happy. Sacco and his colleague, Harald Leschke, to whom the W140’s design was credited, tried to disguise the additional height of the glasshouse, but it remained a feature of the production car. It is alleged that Sacco was dismayed by the corruption of his concept, but Niefer was not to be challenged: bigger, and taller, was what he wanted.
BMW had wrong-footed its Stuttgart rival in 1986 with the launch of its E32 generation 7 Series, which introduced a 5.0 litre V12 engine to power the top range models. Mercedes-Benz could not countenance being trumped by the Bavarian upstart, so delayed the W140 programme for eighteen months to develop its own V12. Naturally, it had to be larger in capacity, so would be a 6.0 litre unit.
The increase in weight of the W140 was partly due to a stronger and heavier bodyshell, but also the much higher level of standard equipment fitted, including double-glazed windows, speed-sensitive power steering, electrically adjustable heated front seats (and rear seats on LWB models), dual zone climate control and self-closing doors and boot lid.
Mercedes-Benz engineers had been developing an ultrasonic rear parking aid for the W140, but it was not yet reliable enough for the production car at launch. Instead, they installed motorised telescopic chrome-plated steel rods that rose automatically from the rear wing tips of the car whenever reverse was selected. This was an elegant, but complex and expensive solution to the problem.
The W140 was not launched with any specific new safety features, but a number were added during its production run. These included side-airbags, Electronic Stability Programme (ESP), Brake Assist System (BAS) Xenon HiD headlamps and rain-sensitive automatic wipers.
One extraordinary miscalculation in the W140’s otherwise meticulous development programme concerned its maximum total payload. Because of the weight of the car itself, the payload was just 402kg (885lbs) for the 300SE and 488kg (1,074lbs) for the 400SE. Potentially, that severely limited its luggage carrying capacity when travelling with five adults on board. That miscalculation would have serious implications for Wolfgang Peter, as we will see later.
In Part Two we will recall how the W140 was received by the motoring press and customers, and discover why Mercedes-Benz would never build another car like this.
Author’s note: How might the W140 have looked if Bruno Sacco’s original concept had not been compromised by Peter and Hornig’s intervention? We investigate this question here.
(1) In the same year, Volvo began fitting three-point lap and diagonal seat belts to its cars, making 1959 the most significant year ever in the evolution of automotive safety.
(2) General Motors was actually the first company to offer optional airbags in some Buick, Cadillac and Oldsmobile models. Its 1974 ‘Air Cushion Restraint System’ (ACRS) was intended to replace, not supplement front seat belts, which were lap-only in ACRS equipped cars. The NHTSA waived the requirement for driver and front seat passenger to wear seat belts in cars so equipped. Despite this, take-up of the option was limited to 10,000 cars and ACRS was dropped in 1976.
(3) The reason for the difference is that the LWB version of the W126 had a 140mm (5 ½”) stretch in the wheelbase over the SWB version, whereas the W140 only had a 100mm (4”) stretch.
(4) ‘The Challenge – Accelerating the Mercedes-Benz Brand’ by Wolfgang Peters and Jürgen Zöllter, published by Delius Klasing.