Ford Mustang Headlight Bulb Size

Additional Notes

• The D3S is an HID (high-intensity discharge) xenon bulb operating at 42V and 35W, built to the ECE standard used in Europe and worldwide. It features a PK32d-5 base with an integral ignitor and is designed exclusively for projector-type housings. The Ford Mustang uses this bulb for both high and low beam functions across the 2015-2018 model years.
• The 9007 is a dual-filament halogen bulb built to the ANSI standard used in the United States and Canada. It operates at 12V with a high-beam filament rated at 65W and a low-beam filament rated at 55W, and it uses a PX29t base. The Mustang specifies this bulb for both high and low beam positions in the 1994-1998 and 2002 model years.
• The 9004 is also a dual-filament ANSI halogen bulb operating at 12V, but its filaments are rated at 65W for high beam and 45W for low beam, and it uses a P29t base rather than the PX29t found on the 9007. Despite their similar appearance, the 9004 and 9007 use different base types, making them non-interchangeable. The Mustang uses the 9004 for both beam positions across the 1987-1993 model years.
• The H6024 is a 7-inch round sealed beam unit conforming to the ANSI standard and operating at 12V. As a sealed beam, the lens, reflector, and filament form a single unit that is replaced as a whole rather than as an individual bulb. The Mustang uses this unit for both beam positions across the 1964-1968 and 1970-1973 model years, with the exception of 1969.
• The 1969 Ford Mustang is a notable fitment exception within the sealed beam era. The high beam position uses the H5001, a 4-inch square sealed beam unit, while the low beam position uses the H5006, a 5.75-inch round sealed beam unit. This makes 1969 the only model year in the specifications where the high and low beam positions take different sealed beam formats from each other.
• The H4651 and its variants H4652 and H4656 are all 4x6-inch rectangular sealed beam units operating at 12V under the ANSI standard. Like all sealed beam types, the entire unit is replaced rather than an internal bulb. The Mustang uses H4651 for the high beam position across the 1979-1983 model years, while the low beam position varies by year, with H4652 specified for 1980, 1982, and 1983, and H4656 specified for 1979 and 1981.
• The split between H4652 and H4656 in the low beam position during the 1979-1983 period reflects a meaningful fitment distinction. Although both are 4x6-inch rectangular sealed beam units, they are separate ANSI designations with different photometric output characteristics, and substituting one for the other is not supported by the specifications.
• Across the full range of specifications, the Ford Mustang has used three distinct headlight technologies: sealed beam units in rectangular and round formats, ANSI dual-filament halogen bulbs, and ECE-standard HID xenon discharge bulbs. Each technology requires a different replacement approach, as sealed beam units involve replacing the entire housing assembly, halogen bulbs are individually replaceable, and the D3S HID bulb includes an integral ignitor that is part of the bulb unit itself.