Porsche 968 front turn signal bulbs use P21/5W size while rear turn signal bulbs use P21W size. The replacement chart covers 1992 to 1995 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 Porsche 968 uses two distinct bulb types across its turn signal positions: the P21/5W at the front and the P21W at the rear, both governed by ECE standards recognized in Europe and worldwide.
Both bulb types operate on a 12-volt electrical system, which is standard for passenger vehicles of this era.
The P21/5W is a dual-filament bulb, meaning it carries two separate filaments within a single envelope, rated at 21 watts and 5 watts respectively.
The P21W is a single-filament bulb rated at 21 watts, serving exclusively the rear turn signal function on the Porsche 968.
The P21/5W uses a BAY15d bayonet base, which features two offset pins at different heights to prevent incorrect installation of the dual-filament bulb.
The P21W uses a BA15s bayonet base, a single-contact fitting with two pins at the same height, which is not interchangeable with the BAY15d base used at the front.
Because the BAY15d and BA15s bases are physically different, the front and rear turn signal bulbs on the Porsche 968 cannot be substituted for one another despite sharing the same 21-watt primary filament rating.
The front and rear turn signal bulb specifications remained unchanged across the full 1992-1995 production run of the Porsche 968.