What is the difference between a 1964 1/2 and a 1965 Mustang?

There is technically no 1964 1/2 in Ford's records. Every early car wears a 1965 VIN. Collectors use the term for the cars built from April to August 1964, and the differences are real.

Key early-car tells

• Charging system: 1964 1/2 cars use a generator. From August 1964, Ford switched to an alternator.
• Engines: The early cars offered the 260 V8, which the 289 replaced for the later 1965 production.
• Details: Early cars have specific horn rings, color-keyed details, seat patterns, and a passenger seat that was fixed on many examples.

Does it matter for value

For most drivers, a clean late 1965 with the 289 is the better car to own. For collectors, a documented early 1964 1/2, especially a convertible with the D-code 289, carries a premium for being part of the launch story. Check the data plate and build date to know exactly what you are looking at.