NSU found itself in deep trouble in the late 1960s because the Wankel engines that it had spent a significant amount of time and money developing had a hard time catching on for a multitude of reasons and cost the company an astronomical amount of money. Its lineup consisted mostly of small, rear-engined cars that were in vogue in the beginning of the decade but quickly fading out of style as the 1970s drew nearer. The bigger and more modern Ro80 was introduced in 1967 but its Wankel engine was notorious for leaking rotor seals, the same problem that plagued many other rotary-engined NSUs.
In 1969, Volkswagen acquired NSU and the projects that its research and development center was working on at the time, including an elegant four-door sedan dubbed K70 that was penned by Claus Luthe (the same man who later drew the BMW E30) and designed to fill the gap between the Prinz and the Ro80. The K in the car’s name stood for kolben (the German word for piston) and indicated that it packed a traditional piston engine as opposed to a rotary mill. The car was scheduled to greet the public for the first time at the 1969 Geneva Motor Show, and a station wagon version was planned later in the production run.
Volkswagen initially cancelled the K70 project, a move heavily criticized by both the press and potential customers who didn’t see the logic in shooting down a new, modern car in order to produce the ancient Beetle and other similar cars. The Wolfsburg-based automaker was not deaf to criticism and ended up giving the K70 the green light for production but there were two catches: The wagon was be delayed and the NSU emblem on the sedan’s front end had to be replaced by a Volkswagen one. Built in Volkswagen’s then-new Salzgitter plant, the K70 was presented to the public in August of 1970.
Designed entirely by NSU from the ground up, the K70 was diametrically opposed to anything that had previously come out of a Volkswagen factory and it earned the honor of being Volkswagen’s first water-cooled, front-engined regular-production model. It was powered by a straight-four engine – Volkswagen’s first – that spun the front wheels, another novel concept for the Wolfsburg-based firm. The public was shocked because it was difficult to envisage a Volkswagen without an air-cooled boxer engine out back.
The carbureted 1.6-liter four-cylinder that powered the K70 was a distant cousin of the Prinz’s 1.2-liter engine. Initially available with either 75 or 90 horsepower, it was mounted longitudinally and linked to a four-speed manual transmission that spun a differential mounted under the engine, approximately where cylinders 3 and 4 are. The mill was tilted 32-degrees towards the passenger side of the car to avoid the whole setup being too tall. Another innovative feature borrowed from the Prinz was the possibility to adjust the valves without removing the valve cover.
The 1.6-liter was joined by a 1.8-liter 100-horsepower four-banger mounted under the hood of the LS model in 1973.
The K70 was a well-executed sedan that won accolades from the motoring press in Europe. It lost the coveted 1971 Car of the Year award to the Citroën GS but it beat the Maserati-powered Citroën SM for second place, an impressive feat to say the least. The car would have undoubtedly had a brilliant career under the NSU banner but its fate was different as part of the Volkswagen lineup: Wolfsburg didn’t want it because it was trespassing on the type 4’s hunting grounds.
The type 4 and the K70 were completely different but they competed against each other because their dimensions, performance figures and price range were very close. The K70 measured 174 inches long (442 centimeters) and weighed 2,380 pounds (1,080 kilos); the 412 was 179 inches long (455 centimeters) and weighed almost exactly 2,380 pounds. The K70 reached 62 mph (100 km/h) from a stop in 13.3 seconds, a task that took the fuel-injected 412 16.5 seconds when equipped with a manual transmission.
The two overlapped in showrooms, too: In 1974, a 412 cost 18,800 francs while a K70 set a buyer back 18,920 francs. By comparison, the Passat ranged from 13,990 for a base two-door model and 17,990 for a range-topping four-door model, and that same year a 911 Turbo cost 48,000 francs and a 1200 sedan (better known as the Beetle) started at 8,990 francs.
To make matters worse the K70 faced internal competition from the Audi 100 that was launched in 1968. With a base price of 19,690 francs, the 100 measured 181 inches (462 centimeters), it weighed 2,403 pounds (1,090 kilos) and reached 62 mph in 12.5 seconds. The 100 looked similar to the K70 which created further confusion between the two cousins.
Overshadowed by the 411/412 and the 100, the K70 posted weak sales numbers year after year and was axed in February of 1975. The Germany-based International K70 Club claims that 210,082 examples were built while other sources cite 211,341 as the correct figure. Although that number is fairly low for a high-volume manufacturer like Volkswagen, it’s very close to the 45,000 K70s that NSU – a much smaller firm – had planned on building annually.
It’s worth noting that the K70 wasn’t the only NSU project that wound up on showroom floors wearing a Volkswagen crest. The project that became the Audi 50 and later spawned the Volkswagen Polo was started by NSU as a replacement for the Prinz. In retrospect, NSU had better-than-even odds at finally offering modern, competitive lineup in the 1970s.
Photos courtesy of Volkswagen’s archives department or scanned out of period documents. We’ve emailed Volkswagen for more high-res shots, check back tomorrow or early next week.