The Audi 100 Series uses an H5001 bulb size for high beam headlights and an H5006 bulb size for low beam headlights. The replacement chart covers vehicle production years spanning 1969 to 1977 with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Audi 100 Series used two distinct sealed beam units across its 1969-1977 model years: the H5001 for high beam and the H5006 for low beam headlights.
Both the H5001 and H5006 are sealed beam units, meaning the lens, reflector, and filament are fused into a single assembly. When a filament fails, the entire unit requires replacement rather than an individual bulb.
The H5001 is a 4-inch square sealed beam unit operating at 12 volts, conforming to ANSI standards recognized in both the United States and Canada.
The H5006 is a 5.75-inch round sealed beam unit, also rated at 12 volts and built to the same ANSI standard applicable in the United States and Canada.
The square form factor of the H5001 and the round form factor of the H5006 reflect physically incompatible housings, making the two units non-interchangeable despite sharing the same voltage rating.
ANSI standardization of both units means that any H5001 or H5006 sealed beam produced to that specification is dimensionally and electrically consistent across manufacturers, allowing cross-brand substitution within the same type.