Diesel supercars are something of an enigma to both diesel enthusiasts and sports car enthusiasts. They have never really found their way into the hearts of either group. In the current era of performance automotive engineering, diesel is driven by massive torque goals, fueled by compound turbochargers and nitrous oxide. Supercars represent the leading edge of gasoline refinement and power transfer.

In the late 1960s, the concept of the supercar had just been proposed to the world. Defined by iconography including the Lamborghini Muira, Ferrari Daytona, and other radically designed machines we were changed forever by the promise of form and function in one harmonious roar. Such a roar as bellowed by the tightly wound V8s and V12s was stifled by the oil crisis of the early 1970s.

The interior of the C-111 is both restrained and racy, as a supercar should be.

With fuel rationing, and the momentum of European automotive influence sweeping the world in tandem, something had to give. Mercedes-Benz has long been known for their globally proven diesel-powered vehicles. From passenger sedans to military vehicles, the compression-ignition powerplant is no stranger to the famed German mark. The Italians may have been the custodians of the first incarnation of the supercar, but the Germans refined the concept. With Porsche stepping in, BMW experimenting, and Mercedes tinkering, exciting creations were rolling out onto test tracks and autobahns.

Jay Leno has the great fortune to be a dedicated car enthusiast with the profile and credibility to open doors. Doors that access some of the rarest and most exotic specimens the world still shelters. In this episode of Jay Leno’s Garage, we are introduced to the stunning Mercedes C-111-II. A car that answered both the Italians in terms of design, and the world in terms of fuel needs. With a series of diesel engines, these experimental concept cars broke records and further solidified the archetype of the supercar.

This 1970 C-111 is a part of Mercedes Classics Center collection, and is one of very few ever produced. Introduced in 1969 at the Frankfurt Autoshow, the first generations of C-111 employed the revolutionary Wankel Rotary engines. Progressing through various generations, the C-111 had two, three, and four-rotor Wankel engines across the first two generations. Mercedes Benz became quickly aware of the issues the Wankel suffered from, and decided if they were to stick to their motto “The Best or Nothing,” they would have to look elsewhere.

One of the 3.5-liter V8s powers this example of the C-111.

With the decreased longevity of the Wankel and the thirsty nature of its fuel consumption, the timing just wasn’t right when gasoline was a scarce commodity. Turning to their roots, Mercedes looked within and decided to repurpose their diesel powerplants for this retro supercar. The 3.0-liter, five-cylinder OM617 was a turbocharged diesel engine from the 240D sedan. Retrofitted for a mid-engine application, this powerplant produced 190 horsepower, and was a considerable step down in power from the rotaries but offered more tolerable mileage. Later versions of the C-111 came equipped with a 3.5-liter gasoline V8 (as seen in this test car).

Transferring power to the ground Mercedes engineers adopted a ZF five-speed transaxle echoing the progressive layout of the Italians. The body of this orange Mercedes is all fiberglass, with a total curb weight coming in at around 2,700 pounds. When considering the power-to-weight of this supercar, you may be underwhelmed. But Leno raises a good point about the first era of supercars saying, “It feels about 205 [horsepower], you have to remember the car is 40-something years old. Back in the day, the most powerful car Ferrari had was 220 horsepower.”

The chassis, suspension, running gear, and other mechanical systems were extensively developed on racetracks, explains Mercedes-Benz Marketing and Communications representative Constantin von Kagene “They did extensive wind-tunnel testing with these cars, a lot of suspension testing, on the rear axles they adapted something that would later become the multi-link rear suspension that we produced in the early ’80s.”

Considering the personality and character of the car, von Kagene describes the C-111 as, “a spiritual successor to the 300 SL, in terms of having a sports car with racing genes.” He later mentions the cars’ development at Stuttgart, Hockenheim, and the Nurburgring, further establishing a pedigree for this spendy side project.

While a total of only 16 cars were produced across four generations, and only two contained diesels, they were the record-setters at Nardo. Diesel is often brushed aside in favor of the charismatic gasoline V8 but don’t forget the contribution of the little 3.0-liter OM617. Cars like this are a history lesson to be enjoyed and studied, they led us to the supercars of today, and may foreshadow the future. Is it time for a modern diesel supercar?