In September 1969, worldwide attention focussed on the C 111 experimental vehicle, which Daimler-Benz presented at the International Motor Show in Frankfurt. This "rolling test laboratory" was a highly conspicuous affair, with its extreme wedge-shaped body, gullwing doors that opened vertically and last but not least, its unusual colour, metallic orange. Just a handful of the cars were produced.
The technical innovations were not quite as obvious: the body consisted of glass fibre reinforced plastic and was riveted and glued onto a steel framework. Some technical features from racing cars were applied to the wheel suspension and last but certainly not least, the car was powered by a three-rotor Wankel engine!
This engine developed some 280hp and allowed the car to reach a maximum speed of 270 km/h. Both figures were remarkable feat at that time.
Only six months later, a highly revised version of the experimental car was presented at the Geneva Motor Show. The new C 111 had a more pleasing body giving better vision and a roomier baggage compartment. It was powered by a
four-rotor 350hp Wankel engine, which gave excellent driving performance: it reached 100 km/h from a standstill in 4.9 seconds and went on to a top speed of 300 km/h.
Although there were many orders and even blank cheques from potential buyers for the car at the factory in Untertürkheim, the C 111 remained a purely experimental vehicle and never went into production.
The super sports car was a favourite object for exhibitions in Germany and abroad and for a long time guaranteed a high level of publicity. Even after Mercedes interest in the Wankel engine had almost passed into oblivion, the C 111 was in the public limelight several times.
In June 1976, in April 1978 and for the last time in May 1979, record speeds were achieved with the C 111 at the high-speed circuit at Nardo in the South of Italy, culminating in several absolute world records over various distances.
For the first two record drives, a 3.0-litre 5-cylinder diesel engine were used. In 1976 engine power was boosted from just 80hp to 190hp with the help of turbochargers and some ancillary measures. When in 1978 an intercooler was added, the car produced 230hp. For the record drive in May 1979, a 4.5-liter V8 engine was taken from series production and bored out to 4.8 litres - and then fitted with two KKK turbochargers! This increased engine power to 500hp at 6200 rpm.
At the record drive in June 1976 the C 111-IID was still easily recognised as a C 111, as it had an only slightly modified exterior compared to the model which had been presented in 1970. But the record cars of 1978 and 1979 no longer had much in common with the original C 111. Only the basic framework stayed the same: the new car had a 100mm extended wheelbase and a reduced track width - down by 150 and 100mm at the front and the rear respectively.
The very long body - now painted silver - was designed exclusively on the basis of aerodynamic principles. After the experience with the car at its record drive in 1978, but also in order to meet the higher speed requirements of the next event, the front section of the C 111-IV's car body was revised and the body was fitted with two tailfins, along with front and rear spoilers. Four international and world records and one absolute circuit world record were achieved with the C 111-IV.
The C 111 must be one of the very few research cars ever powered by such an array of engines - from triple rotor through to five-cylinder diesel to twin turbocharged V8!
C 111 Specifications (First Version)
Engine
| Combustion principle |
Wankel |
| Configuration |
in front of rear axle (mid engine) |
| Engine type |
M 950 F |
| Number of cylinders / arrangement |
three-rotor Wankel engine |
| Total displacement |
chamber volume 3 x 600 cc |
| Compression ratio |
9.3 |
| Rated output |
280 hp / 206 kW at 7000 rpm |
| Rated torque |
294Nm at 4000 - 5500 rpm |
| Fuel system |
direct injection, mechanically controlled; Bosch 3-plunger injection pump |
| Cooling |
water cooling / pump; radiator in the car's front |
| Lubrication |
pressure circulation lubrication |
| Electric system |
12 V |
| Generator |
three-phase AC |
| Starter |
electrical |
| Ignition |
transistor ignition |
| Fuel tank: position / capacity |
in the lateral frame side rails / 2 x 60 litre |
| Fuel supply |
piston pump as part of the injection pump |
Body & Suspension
| Frame design |
sheet steel floor assembly / fibreglass reinforced plastic bodywork |
| Front-wheel suspension |
double wishbone-front axle with torsion bar stabilizer |
| Rear-wheel suspension |
per wheel three wishbones and two trailing arms |
| Front springs |
spring struts, torsion bar stabilizer |
| Rear springs |
spring struts, torsion bar stabilizer |
| Shock absorber front/rear |
telescopic shock absorbers |
| Steering |
recirculating-ball steering |
| Brake system |
hydraulic dual-circuit brake system with vacuum booster; internally ventilated four-wheel disc brakes |
| Parking brake |
mechanical (manually operated), acting on rear wheels |
| Wheels |
sheet-steel wheels or light-alloy wheels |
| Tyres |
195 VR 14 |
| Driven wheels |
rear wheels |
| Drivetrain |
final-drive assembly and differential in unit with transmission |
Gearing & Performance
| Gearing |
5-speed manual transmission ZF 5 DS-25/1 |
| Shifting |
central floor gear shift lever |
| Clutch |
dry single-disc clutch |
| Synchromesh gears |
I - V |
| Final drive ratio |
3.166 |
| Maximum speed |
260 km/h |
| Acceleration 0-100 km/h |
5 sec (2 occupants) |
C 111 Specifications (Second Version)
Engine
| Combustion principle |
Wankel |
| Configuration |
in front of rear axle (mid engine) |
| Engine type |
M 950 F |
| Number of cylinders / arrangement |
four-rotor Wankel engine |
| Total displacement |
chamber volume 4 x 600 cc |
| Compression ratio |
9.3 |
| Rated output |
350 hp / 257 kW at 7000 rpm |
| Rated torque |
392Nm at 4000 - 5500 rpm |
| Fuel system |
direct injection, mechanically controlled; Bosch 4-plunger injection pump |
| Cooling |
water cooling / pump; radiator in the car's front |
| Lubrication |
pressure circulation lubrication |
| Electric system |
12 V |
| Generator |
three-phase AC |
| Starter |
electrical |
| Ignition |
transistor ignition |
| Fuel tank: position / capacity |
in the lateral frame side rails / 2 x 60 litre |
| Fuel supply |
piston pump as part of the injection pump |
Body & Suspension
| Frame design |
sheet steel floor assembly / fibreglass reinforced plastic bodywork |
| Front-wheel suspension |
double wishbone-front axle with torsion bar stabilizer |
| Rear-wheel suspension |
per wheel three wishbones and two trailing arms |
| Front springs |
spring struts, torsion bar stabilizer |
| Rear springs |
spring struts, torsion bar stabilizer |
| Shock absorber front/rear |
telescopic shock absorbers |
| Steering |
recirculating-ball steering |
| Brake system (Foot brake) |
hydraulic dual-circuit brake system with vacuum booster; internally ventilated four-wheel disc brakes |
| Parking brake (Hand brake) |
mechanical (manually operated), acting on rear wheels |
| Wheels |
sheet-steel wheels or light-alloy wheels |
| Tyres |
205 VR 14; for racing: front: 4.50/11.60-15; rear: 5.50/13.60-15 |
| Driven wheels |
rear wheels |
| Drivetrain |
final-drive assembly and differential in unit with transmission |
Gearing & Performance
| Gearing |
5-speed manual transmission ZF 5 DS-25/1 |
| Shifting |
central floor gear shift lever |
| Clutch |
dry double-disc clutch |
| Syncromesh gears |
I - V |
| Final drive ratio |
2.975 |
| Maximum speed |
300 km/h |
| Acceleration 0-100 km/h |
4.8 secs (2 occupants) |
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