Wankel engine
NSU is primarily remembered today as the first licensee and one of only four automobile companies to produce cars for sale with rotary "Wankel engines". NSU invented the principle of the modern Wankel engine with an inner rotor. The NSU Ro 80 was the second mass-produced two-rotor Wankel-powered vehicle after the Mazda Cosmo. In 1967, NSU and Citroën set up a common company, Comotor, to build engines for Citroën and other car makers. Norton made motorcycles using Wankel engines. AvtoVaz (Lada) manufactured single and twin rotored Wankel powered cars in the early 1980s. Only Mazda has continued developing the Wankel engine and made several more cars with the Wankel engine.