In 1963, the M20D was introduced, essentially an M20C with fixed landing gear and a fixed-pitch propeller. This had a slightly lower price than the M20C and was intended as a basic or trainer model which would have lower insurance costs and which would compete with the Piper Cherokee 180. It could be upgraded with retractable landing gear, and in fact, most of them were upgraded over the years. The M20D was produced from 1963 to 1966 with a total production of 161 units. In 1964 the M20E Super 21 was introduced. It was also based on the M20C but with a more powerful Lycoming fuel-injected engine. The company sold 366 M20E units that year.