The BMW 128i uses D1S and H7 bulb sizes for both high beam and low beam headlight applications, with the specific bulb size varying by production year. A replacement chart covering 2008 through 2013 model years documents the headlight bulb specifications for this vehicle.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The BMW 128i carried two distinct headlamp system options across its 2008-2013 model years, with the specific bulb required for both high beam and low beam positions determined entirely by which headlamp system the vehicle was built with.
The D1S is a High-Intensity Discharge xenon bulb rated at 85V and 35W. It features a PK32d-2 base with an integral ignitor built into the bulb body, and it is designed specifically for projector-type housings rather than reflector-style assemblies.
The H7 is a single-filament halogen bulb rated at 12V and 55W, fitted with a PX26d base. Unlike the D1S, it carries approval not only under ECE standards used in Europe and worldwide markets but also in the United States and Japan.
Both the D1S and H7 are ECE-standardized bulb types, meaning their physical and electrical specifications conform to internationally recognized regulations rather than proprietary formats.
On the BMW 128i, the D1S serves the same socket position as the H7 depending on headlamp type, functioning as both the high beam and low beam source within HID projector housings. The two bulb types are not interchangeable, as they differ in base design, operating voltage, and housing compatibility.
The D1S requires a ballast and ignitor circuit to strike and sustain its arc discharge, whereas the H7 operates directly on a standard 12V automotive circuit without additional control hardware.
Because the D1S incorporates an integral ignitor, it is a self-contained unit that does not require a separately mounted external ignitor, which distinguishes it from other HID bulb types in the D-series family.
The halogen and HID fitments for the 128i remained unchanged across the full 2008-2013 production span, with no variation in bulb size by year within either headlamp system type.