The BMW 430i high beam and low beam headlight bulbs both utilize the D1S size. The replacement chart covers 2017 to 2018 vehicle 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 D1S bulb type is specified for both high beam and low beam headlight positions on the BMW 430i across the 2017-2018 model years, applying exclusively to vehicles equipped with HID headlamps.
The D1S is a High-Intensity Discharge (HID) xenon bulb operating at 85 volts and 35 watts, which places it in a category distinct from standard halogen bulbs in terms of both electrical requirements and light output characteristics.
A defining feature of the D1S is its integral ignitor, meaning the ignition component is built directly into the bulb unit rather than housed separately in the vehicle's ballast system, which affects how the bulb is replaced and what components are involved.
The D1S uses a PK32d-2 base, a keyed connector design that physically prevents incorrect bulb installation and is not interchangeable with other HID base types such as D2S or D3S.
The D1S is designed specifically for projector-type headlight housings, and its use in reflector-type housings would produce improper light distribution.
The D1S conforms to ECE (Economic Commission for Europe) standards, a regulatory framework recognized across Europe and many other markets worldwide, governing the bulb's photometric and safety performance.