The Ferrari Mondial t uses a 158 bulb size for both front and rear side marker applications. The replacement chart covers 1989 to 1993 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Ferrari Mondial t uses the 158 bulb for both front and rear side markers across the full 1989-1993 production run.
The 158 is a miniature wedge-base bulb built to the T10 form factor, which refers to a tubular glass envelope roughly 10 thirty-seconds of an inch wide.
The wedge base design means the bulb is held in place by the socket gripping the glass pinch at its base, with no separate metal base or bayonet pins involved.
The 158 operates at 12 volts and draws 3 watts, placing it among the lower-wattage bulbs in automotive applications.
The 158 conforms to ANSI standards recognized in both the United States and Canada, meaning it is a standardized part rather than a proprietary one.
Because the front and rear side marker positions on the Mondial t share the same 158 bulb, a single bulb type serves all four side marker sockets on the vehicle.
T10 wedge bulbs are a widely produced form factor, and the 158 designation identifies a specific wattage and voltage rating within that family rather than a unique physical shape.
The uniform fitment of the 158 across both positions and all five model years indicates no mid-cycle revision was made to the side marker lighting specification on the Mondial t.