The production of Diesel engines started in 1899, when the Hungarian engineers Oszkár Epperlein (2nd Director of FEG) and Jenő Böszörményi purchased the patent rights of Diesel engines for the FEG company from his collaborator Rudolf Diesel.
On the threshold of World War I., changes due to the growing demand for arms production did not overshadow products with which the factory was also competitive. It is fair to say that, in addition to weapons, these products have helped to establish the reputation of the factory and have earned respect for the workers of the Weapons and Machinery Factory around the world. After all, Diesel engines, machine tools, various mass goods have reached England, Austria, France, Greece, Germany, Russia and Spain, as well as the American continent (North, Central and South America), Australia, Africa, China and Japan.