Mercedes-Benz C 111.

Experimental vehicle, super sports car and style icon.

Experimental vehicle, super sports car and style icon.

Frankfurt, September 1969: expectations were already running high. Rumours had been circulating for quite some time that Mercedes-Benz was planning to launch a sensation at the International Motor Show (IAA) in Frankfurt. But the car finally unveiled by the Stuttgart manufacturer surpassed even the wildest expectations. What the journalists got to see was a super sports car with gullwing doors and a Wankel rotary engine. It was a research vehicle that quickly became the absolute dream car of the 1970s.

Research and innovation.

The Mercedes-Benz development engineers had started work as far back as in 1967. Although the result frequently gave rise to speculation that the aim had been to build a successor to the legendary 300 SL “Gullwing”, the goal was in fact quite different. From the very start, the C 111 was conceived purely as an experimental vehicle. One of the objectives was to test the use of glass-fibre-reinforced plastic for automotive bodyshells. The car was, in addition, to be used for the testing of a new engine concept: the rotary piston engine designed by Felix Wankel.

Engineering and design.

The concept as a whole made the C 111 the absolute dream car of the seventies. Its engineering lived up to the promise of Bruno Sacco’s futuristic styling. Both the C111-I of 1969 with its three-rotor Wankel engine (206 kW/280 hp) and the C 111-II of 1970 with four-rotor Wankel engine (257 kW/350 hp) impressed with their effortlessly superior driving performance, delivering top speeds of 270 and 300 km/h respectively, while the C 111-II could accelerate from a standing start to 100 km/h in 4.9 seconds. Yet even when the Mercedes-Benz engineers pushed the Wankel engine to the very limits of its design, the result did not meet the high standards of Mercedes-Benz in terms of reliability and durability. The more stringent emissions legislation in the United States was to prove an added complication.

Series production remained a dream.

But it was not only the disadvantages of the rotary piston engine that ultimately led to the decision not to proceed further with series production of the C 111. By the early 1970s, passive safety was becoming a more and more important factor in automotive development. The plastic bodyshell of the C 111 had an inherent disadvantage in this respect, compared with a conventional sheet steel body. And so it was that, in 1971, Mercedes-Benz made the decision not to move forward with series production of the sports car. The dismay among automobile enthusiasts was considerable. More than one such fan had taken a punt and submitted an order to the plant at Untertürkheim, along with a blank cheque – all to no avail.

Second career as a record-setter.

So although it would never be allowed to cruise the country lanes and boulevards, the C 111 would go on to make its mark on the world’s test circuits. By 1973 the growing importance of fuel-efficient engines had become clear, not least as a result of the oil crisis, presenting good opportunities for thrifty diesels. In an attempt to disprove the compression-ignition engine’s reputation as loud and lacking dynamism, the test department fitted the C 111-II with a three-litre five-cylinder diesel engine. Now known internally as the C 111-II D, the test vehicle used turbocharging and intercooling systems to produce 140 kW (190 hp) from the OM 617 LA production engine (59 kW/80 hp) taken from the 240 D 3.0 of the W 115 series (“Stroke Eight”). In June 1976 the C 111-II D delivered a convincing performance on the test circuit at Nardò in Italy: over the space of 60 hours, four drivers set 16 world records, among them 13 for diesel vehicles and three for cars with any type of engine. Their average speed was 252 km/h – proving that a Mercedes-Benz diesel engine is also more than capable of sprinting.

And these would not remain the only records set. The successor model, the C 111-III - now with a diesel engine producing 169 kW/230 hp – went on to take a further nine world records in 1978. In 1979 the last version of the car – the C 111-IV with a 4.8-litre V8 petrol engine (368 kW/500 hp) - drove at 403.978 km/h to break the world circuit record.

Mercedes enigma.

1969 will go down as a special year for Mercedes-Benz. Rumours had been circulating for a long time that the inventor of the motor car was working on a sensation. At the International Motor Show in Frankfurt the secret was finally revealed – and it really is a sensation: the C 111, a super sports car with gullwing doors and a  Wankel rotary engine. The industry was dumbstruck, the press couldn’t get enough of it and the public were bowled over. Not long after, in the spring of 1970, the even more attractive and even more powerful variant of the C 111 experimental vehicle was unveiled – and it quickly became the unrivalled dream car of an entire  generation.

Source: ‘Autocar′, 11 September 1969

'The “big hit” of the IAA is not for sale.'

Source: ‘Trierische Landeszeitung′, 23 August 1969

An exclusive Wankel torpedo.

Superb concept and design. The C 111 epitomises the special inventiveness and passion of the Mercedes-Benz designers and engineers. Their mission: to come up with the superlative sports car. To this end they have developed a vehicle body made of fibreglass-reinforced plastic, which is riveted and glued to a steel frame floor. This technology makes it possible to build a very light and stable vehicle solid roadholding is assured by the chassis,

which is up to motorsports standard and has impressed even professional racing drivers. The second version of this 300 km/h thunderbolt is propelled by a 350 hp (257 kW) four-rotor Wankel engine. Its turbine-like characteristics and incredible output figures make this vehicle concept perfect. Mission accomplished.

Source: ‘Linzer Volksblatt′, 23 August 1969

The motor car that takes the breath away.

Trendsetting design. Mercedes-Benz writes automotive history with the distinctive gullwing doors. The 300 SL  “Gullwing″ was the first sports car to include this spectacular design feature that is also such a highlight of the C 111. The unique and striking appearance of the C 111 is unmistakeable and cutting-edge even today. Together with its distinctive orange

metallic paint finish, its design idiom is that of the super sports car. The vehicle interior is more functional, but no less striking for that: contoured bucket seats, a well-arranged dashboard and countless display instruments make it clear that the driver is truly in control here.

Source: ‘DAZ′, 20/69

Now even faster and more powerful.

A winged vision. The presentation of the C 111 to the public and its ascent to style icon status is pulling in the customers fast. The experimental vehicle, which Mercedes-Benz is using to test out innovative technologies and develop them to series production readiness, embodies sportiness, progress and visions of the future like no other motor car of its era.

And the aura of this super sports car permeates through to the present – the trade press and lifestyle media continue to write about this exceptional motor car to this day. But there is one fact about this dream car that will never change: it is not for sale, to anyone.

Source: ‘Motor-Rundschau + Kritik′, 6/70

Technical data.

Model Mercedes-Benz C 111/ II
Year of construction 1970
Engine Four-rotor Wankel engine
Total displacement chamber volume 4 x 600 cc
Rated output 350 hp / 257 kW at 7000 rpm
Acceleration 0 to 100 km/h in 4.8 s
Top speed 300 km/h
Wheelbase 2,620 mm
Length x width x height 4,440 x 1,800 x 1,120 mm
Rated torque 40 mkg at 4000 - 5500 rpm

'Shapely Sports Machine'

Source: ‘The Evening Post′ (Wellington), 21 August 1969

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