The BMW 550i uses D1S and H7 bulb sizes for both high beam and low beam headlight applications, with the specific bulb size varying by model generation. A replacement chart covering 2006 through 2016 model years documents the headlight bulb specifications across the vehicle's production span.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The D1S is a high-intensity discharge (HID) xenon bulb operating at 85V and 35W, fitted with a PK32d-2 base and a built-in ignitor. Its design is specific to projector-type housings, which shapes how it distributes light compared to reflector-based systems.
The H7 is a single-filament halogen bulb rated at 12V and 55W, using a PX26d base. Both the D1S and H7 are manufactured to ECE standards, meaning they are approved for use in Europe and worldwide markets. The H7 also carries approval in the United States and Japan.
The BMW 550i carries dual high beam fitment across most of its model years, with both D1S and H7 listed as valid sizes depending on the headlamp system installed on the vehicle. These two bulb types are not interchangeable, as they differ in operating voltage, wattage, base type, and the housing technology they require.
For the 2011-2013 model years, the high beam specifications list D1S and H7 without a qualifying headlamp-type note, while surrounding years explicitly label the condition as "With HID Headlamps" or "With Halogen Capsule Headlamps." The underlying fitment logic remains the same across all years.
In the low beam position, the 2011-2013 550i lists only the D1S with no halogen alternative, whereas the 2008-2010 and 2006-2007 model years include both D1S and H7 options depending on headlamp type.
For the 2006-2007 high beam position, only the H7 is listed, while the low beam for those same years accommodates both D1S and H7 depending on the headlamp system. This means the headlamp configuration on those vehicles determines whether a single bulb type or two distinct types are present across the high and low beam positions.
Because the D1S integrates its ignitor directly into the bulb body, replacement involves the ignitor as part of the unit rather than as a separate component. This is a relevant distinction when sourcing a replacement, as the ignitor is not a separately serviceable part on this bulb type.
The presence of two distinct bulb types across the same model year reflects that the 550i was available with different headlamp assemblies. Confirming which assembly is installed on a specific vehicle is necessary before selecting a replacement bulb, as installing the wrong type is not supported by the housing design.