By the 1966 model year, Ford was having difficulty handling the outrageous demand for new Mustangs, even with three fully functioning assembly plants focusing on nothing else. There were very few changes between the ‘65 and ‘66 model years. 1966 Mustangs came with a 200 CU, in-line six cylinder standard engine. Although the three original transmission options remained (3 speed, 4 speed, and automatic) most of the ‘66 models were ordered or later equipped with the automatic option. The instrument panel from the Mustang GT was repurposed to come standard with all models, and new 14 inch tires came standard on the ‘66 Mustangs. Other than the tires and details of the gas caps and emblems, the exterior styling was the same between the 1966 and 1965 models. An exciting new option this year included the AM-FM radio and AM/eight-track stereo, as well as a number of new color options for paint and interior.

Once again, a Fastback, convertible, and coupe were the three main options to choose from. The 1966 Mustang convertible was the number one selling convertible of the year, by a long shot. The second, the Impala, sold little more than half the number of Mustangs. In March of 1966, the Mustang made car history (again) when the millionth Mustang rolled off the assembly line. Accordingly, 1966 was another incredible year of sales for the Ford Mustang, and the ‘66 has gone down in history as one of the best.