The long history of Mercedes-Benz spawned plenty of amazing projects, many of which resulted in some of the greatest road-going and racing vehicles, we have ever seen. You only need to look at cars like the 300SL, 300SLR, CLK GTR, SLR McLaren, and others. There are, however, many cars that never saw the light of day. Among the most obscure projects to come out from Mercedes-Benz’s test facilities is the 1991 Mercedes C112. It had the potential to be the most ground-breaking sports car of the 1990s, but sadly, Mercedes decided not to make it.

It was built as a test bed

Mercedes unveiled the C112 at the 1991 Frankfurt Auto Show. As with many prototypes, its purpose was to showcase the latest technological advancements of the German brand that would make it into future Mercedes models. It’s, technically, a successor to the 1970 Mercedes C111, which, unlike the C112, was produced in multiple copies – 16 to be exact.

Mercedes C112 was a race car for the road

While many cars were marketed as “a race car for the road”, this fully applied to the C112, or at least it would have, had they actually produced it in a quantity. In essence, the 1991 Mercedes C112 was the road-worthy counterpart to the Mercedes Sauber C11 Group C race car, built for the 1990 World Sports-Prototype Championship. While both cars shared some design decisions, they did not share much in terms of powerplant or drivetrain.

While its predecessor, the C111, featured pop-up headlights, the C112 came with fixed headlights with clear lenses, like what we see on many modern-day cars. The design made for a more streamlined design, which greatly reduced drag. To keep aerodynamic turbulence to a minimum, the C112 featured only three air intakes. One at the front and two flanking the sides.

The one at the front supplied air to the front-mounted heat exchanger/radiator and cooled the front brakes. The ones on the sides of the C112 were separated into two sections. The larger section directed air to the engine while the smaller sections cooled the rear brakes.

With little in the way of crests and curves, A-pillar-mounted wing mirrors and flush door handles, the Mercedes C112 had a drag coefficient of 0.30 – the lowest of a sports car at the time.

Active aerodynamics

The aerodynamic trickery of the C112 does end with the above-mentioned design decisions. After the Porsche 959, the Mercedes C112 was the second high-performance sports car to feature active aerodynamics. The C112 featured an active front splitter that automatically adjusts its angle, depending on the speed and conditions. Moreover, the rear wing, which was normally, flush with the body, would serve as an air brake in order to aid in stopping the car from high speeds.

German engineering meets Italian styling

Like many other high-performance carmakers, Mercedes turned to an Italian coachbuilder for the C112’s body. Responsible for turning Bruno Sacco's design into reality was the Turin-based studio, Carrozzeria Coggiola. The body, itself, was made from aluminum and Kevlar body panels. The engineering aspect of the C112 was headed by Karl Hoehl, who was in charge of a select team of 20 engineers.

The chassis was done in-house by Mercedes and consisted of bonded aluminum chassis with a steel tubular sub-frame with an integrated roll-cage. The bonded aluminum chassis weighed just 130 pounds (59 kg). Fully assembled, the Mercedes C112 had a curb weight of 3,459 pounds (1,569 kg). The suspension was a multi-link setup, derived from the Mercedes 190 Series, also known as the "Baby Benz".

Gullwing doors with safety in mind

The gullwing doors were an obvious throwback to the 1954 Mercedes 300SL. On the C112, the gullwing doors were servo-assisted through hydraulic cylinders, mounted under the roof. You may remember that in the Mercedes SLS AMG, the upper door hinges of the gullwing doors would explode in the case of a roll-over accident in order to provide emergency access. In the C112, the gullwing doors were specially designed to bend, should the car roll over.

Powered by one of the most legendary V-12 engines

Unlike the Sauber-built Group C race car, which was powered by the M119, 5.0-liter V-8 unit, the C112 relied on a mid-mounted M120, 6.0-liter, 60-degree, V-12 with 408 horsepower at 5,200 RPM and 428 pound-feet (580 Nm) at 3,800 RPM, which was mated to a ZF six-speed manual transaxle.

The engine would go on to power, in one form or another, some of the more exciting Mercedes models of the 1990s and early-2000s such as the R129 SL600 and SL73 AMG, as well as exotics like the Isdera 112i Commendatore, Pagani Zonda, and others. A quad-turbo variant was also used in the Chrysler M4 Four-Twelve concept.

While the C112 was never tested in the real world, the 0 to 62 mph (100 km/h) was said to be in 4.9 seconds while the top speed was 192 mph (309 km/h). Theoretically, the car could generate a maximum downforce of 2,200 pounds (998 kg).

Mercedes-Benz C112 specifications

Engine

6.0-liter, 60-degree, V-12

Power

408 HP @ 5,200 RPM

Torque

428 LB-FT @ 3,800 RPM

Transmission

ZF six-speed manual

0 to 62 mph

4.9 seconds

Top speed

192 mph

Weight

2,200 pounds


The C112 was the first car to feature Active Body Control

The C112 was a developmental prototype for many advanced systems, including Mercedes’ ABC suspension or Active Body Control. The adaptive suspension system works with hydraulics, active springs, and sensors, with the car’s ECU adjusting the suspension accordingly, depending on the driving conditions.

Another high-tech (for the time) feature was the rear-wheel steering, which only served to improve directional stability. The system was not meant to improve low-speed maneuverability such as when parking the car. There was also a tire-pressure monitoring system – a system that would be made widely available much later.

The C112 wanted to be a more civilized sports car

Mercedes has always been big on luxury, which is why, unlike most 1990s, high-performance mid-engine cars, the C112 was meant to be more usable and luxurious. In 1989, Mercedes brought out a much more radical concept – the F100. It was a glimpse of the future family car, with a single-box design and a central driving position.

Realizing that the F100 concept was too ahead of its time, Bruno Sacco’s design department, known as DAS, decided to take a slightly more conventional approach when designing the Mercedes C112. The car may have drawn some inspiration from the Sauber C11 Group C racer, but it was not meant to recreate the harsh reality of racing.

The C112 came with plenty of amenities such as automatic climate control, tire-pressure monitoring, power-assisted steering, brakes, and clutch, and well-padded bucket seats. Most of the interior was finished in high-quality leather, including the dashboard.

It was an instant attention-grabber

While the C112 was never meant to be more than a show car and a developmental prototype, around 700 orders for the car came in, during the 1991 IAA Frankfurt Auto Show. Despite the car being thoroughly developed, Mercedes just didn’t feel like bothering to produce the car, even in limited quantities.

To this day, the 1991 Mercedes C112 remains one of the most technologically advanced sports cars of its time that never made it to production. Only one was ever made and it resides at the Mercedes Museum, in Stuttgart. The C112’s value is estimated at $3 million, but the one-off is not for sale.