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.