In 1934 Porsche produced three types of proto-type tractors, all equipped with a gasoline engine. The unique design of the diesel engine with its air-cooled feature was not quite ready for mass production. By the early 1950's four basic models had been designed: 1 cylinder, 2 cylinder, 3 cylinder and 4 cylinder. In 1956 Mannesmann AG wanted to get into the tractor business and purchased a license for the Porsche diesel engine design. By rebuilding the old Zeppelin factory into a state-of-the-art manufacturing facility Mannesmann AG was able to begin manufacturing highly sophisticated Porsche diesel engine systems within their tractors. Between the year of 1956 and 1963 over 125,000 Porsche diesel-powered tractors were manufactured. Within this same time frame the American side of the corporation sold roughly 1,000 Porsche-Diesel tractors in North America. Juniors and Supers being sold most often, as Standards and Masters just weren't price-competitive enough with U.S. made tractors.
