Ferrari 348 TB front and rear side marker bulbs use a 158 size bulb for replacement applications. The replacement chart covers vehicle production spanning 1990 to 1992.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Ferrari 348 TB uses the 158 bulb for both its front and rear side markers across the 1990-1992 model years.
The 158 is classified as a miniature wedge bulb, corresponding to the T10 form factor, which refers to a tubular bulb body approximately 10mm wide with a wedge-style base that seats without a separate socket locking mechanism.
The 158 bulb operates at 12 volts and draws 3 watts, placing it in the low-wattage range typical of marker and indicator lighting rather than primary illumination functions.
The 158 designation follows the ANSI standardization system used in the United States and Canada, meaning the bulb conforms to a defined set of electrical and physical parameters recognized across those markets.
Because the same bulb size applies to both the front and rear side marker positions on the Ferrari 348 TB, a single bulb type serves all four side marker locations on the vehicle.
The T10 wedge base format is shared by several ANSI-coded bulbs, and substitution with visually similar wedge bulbs of differing wattage or voltage ratings would fall outside the specified parameters for this vehicle.