NSU - Ro80
The NSU Ro 80 was a technologically advanced large sedan-type automobile produced by the German firm of NSU from 1967 until 1977. Most notable was the powertrain; a 113 bhp (86 kW), 995 cc twin-rotor Wankel engine driving the front wheels through a semi-automatic transmission employing an innovative vacuum system. It was voted Car of the Year for 1968 by European motoring writers. Unfortunately for NSU, the car developed an early reputation for unreliability, from which it would never escape. The Wankel engine in particular suffered from heavy wear on the rotor tip seals, among many other problems, and some early cars required a completely rebuilt engine before 30,000 miles (50,000 km), with problems visible as early as 15,000 miles (24,000 kilometres). Poor understanding of the Wankel engine by dealers and mechanics did not help this situation. By the 1970 model year, most of these problems were resolved, but a necessarily generous warranty policy and damage to the car's reputation had undermined NSU's financial situation irreparably and NSU was acquired by Audi (of the Volkswagen group) in 1969.
NSU Ro80 1971
NSU Ro80 in Aero-blue metallic
NSU Ro80 1974
NSU Ro80 in Agate Brown
Other technological features of the Ro 80 aside from the powertrain were the four wheel disc brakes, which for some time were generally only featured on expensive sports or luxury saloon cars. The front brakes were mounted inboard, reducing the unsprung weight. The suspension was independent on all four wheels, with MacPherson struts at the front and semi-trailing arm suspension at the rear, both of which are space-saving designs commonly used today. Power assisted rack and pinion steering was used, again foreshadowing modern designs.
The car featured an automatic clutch which was commonly described as a three-speed semi-automatic gearbox: there was no clutch pedal but instead, on top of the gearknob, an electric switch that operated a vacuum system which disengaged the clutch. The gear lever itself then could be moved through a standard 'h pattern' gate.
The styling, by Claus Luthe who was head of design at NSU and later BMW, was considered very modern at the time and still holds up well; the Ro 80 has been part of many gallery exhibits of modern industrial design. The large glass area foreshadowed 1970s designs such as Citroën's. The shape was also slippery, with a drag coefficient of 0.355 (practically unequaled for the era, although average for modern cars). This allowed for a top speed of 112 mph (179.2 km/h). Series production started in October 1967: the last examples came off the production line in April 1977. There were 37,204 vehicles produced during the ten year production run.