Porsche 930 front and rear side marker bulbs utilize a 3893 size bulb across both locations. The replacement chart covers 1978 to 1979 production years 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 Porsche 930 uses the 3893 bulb across both its front and rear side marker positions for the 1978-1979 model years.
The 3893 is an ANSI-standardized bulb, meaning it conforms to a defined set of electrical and physical specifications recognized across the United States and Canada.
The 3893 bulb operates on a 12-volt electrical system, which is consistent with standard automotive voltage architecture.
A defining characteristic of the 3893 is its dual-filament construction, meaning the bulb contains two separate filaments within a single envelope, each capable of operating independently.
The 3893 uses a BAY15d bayonet base, a two-pin offset base type where the two pins are positioned at different heights along the base, a design that prevents incorrect insertion orientation.
The BAY15d base is directly associated with dual-filament bulbs, as the offset pin configuration ensures each filament connects to the correct circuit contact.
The 3893 is classified as a specialty application bulb, indicating it is not among the most broadly distributed automotive bulb types and may have a narrower range of direct substitutes.
The front and rear side marker positions on the Porsche 930 share an identical bulb specification for 1978-1979, meaning a single bulb type services all four side marker sockets on the vehicle.