John Deere's Model 4020 was made to replace the Model 4010. The 4020 came with a six-cylinder engine, capable of 96 horsepower and their Syncro Range transmission. It was standard in the 4020s and allowed users to operate at 8 forward speeds and 2 reverse speeds. Between 1963 and 1972, over 184,000 tractors were sold, selling for about $10,345 each. The Model 4020 was the most popular tractor of its time and was eventually replaced by the 4230 in 1972.