The Porsche 718 Cayman high beam and low beam headlight bulbs both use the D3S size. The chart contains replacement bulb specifications covering the 2017 to 2021 production range.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
ECE standard (Europe & worldwide). Mercury-free HID (xenon) discharge bulb with PK32d-5 base and integral ignitor, for projector-type housings. 42V, 35W.
The D3S is the sole bulb type specified across all listed years and positions for the Porsche 718 Cayman, appearing in both high beam and low beam roles.
The D3S is a High-Intensity Discharge (HID) xenon bulb operating at 42 volts and 35 watts, designed for projector-type headlight housings.
Unlike older HID bulb types, the D3S incorporates an integral ignitor, meaning the ignitor is built directly into the bulb unit rather than housed separately within the ballast circuit.
The D3S uses a PK32d-5 base, which is a keyed connector format specific to this bulb family and is not interchangeable with other HID base types such as D1S or D2S.
The D3S is classified as mercury-free, conforming to environmental regulations that restrict hazardous substances in electrical and electronic equipment.
The D3S carries ECE certification, indicating compliance with European and internationally recognized lighting standards rather than SAE/DOT standards used in North America.
For the 2017-2019 model years, the D3S fitment is explicitly conditioned on the vehicle being equipped with HID headlamps, indicating that alternative headlamp configurations existed during that period.
The 2021 model year lists the D3S without a conditional HID notation, suggesting that HID headlamps were the standard configuration for that year rather than an optional one.
Because the D3S integrates its ignitor, substituting a D1S or D4S bulb, which share the same wattage and voltage ratings, is not a valid interchange due to differing ignitor and base configurations.
The shared D3S specification across both high beam and low beam positions in each listed year indicates the 718 Cayman uses a single bulb type to serve both functions, consistent with projector-based bi-xenon headlight systems.