Claus Luthe - Career - NSU

NSU

He soon, however, joined NSU, where he was instrumental in developing the company’s design department. Luthe’s first designs at NSU were the second-generation NSU Prinz 4 and the NSU Wankel Spider.

The Prinz had a distinct resemblance to its contemporary Chevrolet Corvair; the original design had already been finalized when BMW launched its new 700 model in 1959, with a very similar design. NSU management decided that changes were needed, and an NSU board member who had just returned from the United States described the Corvair design to Luthe, who incorporated some of the elements into the Prinz's bathtub design.

With the growth of the German economy, NSU was interested in offering larger cars to the growing middle class, and in 1962 NSU president Gerd Stieler von Heydekampf authorized the development of a mid-sized front-wheel drive sedan, using the company's revolutionary new Wankel engine technology. Chief engineer Ewald Praxl was given the assignment to develop the car, originally envisaged at 800 kg and 80 hp, starting from a clean sheet.

Luthe was given responsibility for the design, working with the engineering team of Walter Froede and Georg Jungbluth, to utilize the compact Wankel engine, itself created by Felix Wankel. Luthe created a clean wedge shape with a large glasshouse, while the engineering team added innovations such as four-wheel independent suspension, semi-automatic transmission and inboard disc brakes to reduce unsprung mass. The Ro 80 still stands today as a milestone in automotive design. It had an initial drag coefficient of only 0.35, remarkably low for its time, even though it was not tested in a wind tunnel until the design was largely finalized. The final production models dropped the drag coefficient to 0.34.

"After these wind tunnel tests, the outer shape of the body was not modified at all. We got, however, new insights into the airflow through the engine compartment and the possible air outlets for the passenger room. These could have been moved to the rear end of the boot, but the improvement was so marginal and the cost involved so high that these outlets remained in the C-column."

In late 1967, when the remarkable new Ro 80 was introduced at the Frankfurt Motor Show, it did not initially gain universal acceptance for its unconventional wedge-like design. However, sales proved to be strong, and by the spring of 1969, there were still waiting lists for the car. Unfortunately the early engines suffered from heavy wear of the rotor tip seals in the innovative Wankel engine, causing severe financial losses for NSU. 37,204 Ro 80s were built by the time production finally ceased in 1977, but by that time the company had long been part of Audi, a Volkswagen subsidiary.

The K70 was originally created by Luthe as the NSU K70, to fill the gap between the Prinz and the Ro 80, but came to the market in 1971 as a Volkswagen K70, after considerable delays, partly due to the Volkswagen acquisition of NSU, and with modifications to Luthe's original design.