Ferrari 348 GTB front and rear turn signal bulbs use 1156 size bulbs for both locations. The replacement chart covers 1993 to 1994 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 Ferrari 348 GTB uses the 1156 bulb across all listed turn signal positions for the 1993-1994 model years.
The 1156 is a single-filament bulb, meaning it is designed to perform one lighting function rather than serving dual purposes such as combined stop and tail operation.
It operates on a 12-volt electrical system and draws 21 watts, which is consistent with standard automotive incandescent turn signal applications.
The 1156 uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin, distinguishing it from the dual-contact BA15d variant used in other bulb types.
The 1156 designation follows ANSI standards applicable to the United States and Canada, indicating the bulb conforms to a defined set of dimensional and electrical specifications recognized across North American markets.
Both the front and rear turn signal positions on the Ferrari 348 GTB share the same 1156 bulb specification, meaning a single bulb type serves all four turn signal sockets on the vehicle.
The BA15s bayonet base requires a push-and-twist installation method, which is a common fitment style in automotive sockets but is not interchangeable with screw-base or wedge-base socket types.
Because the 1156 is a single-filament type, substituting it with a dual-filament bulb such as the 1157, which shares a visually similar form but uses a BA15d base with two pins, would result in an incompatible fitment.