BMW M4 Brake Bulb Size
The BMW M4 brake light utilizes a specific H21W bulb size for illumination purposes. Data for the specified vehicle covers a period spanning from 2015 through 2018.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
Bulb Size by Year Range
| Years | Bulb Size |
|---|---|
| 2015-2018 | H21W |
Bulb Specifications
| Description | Bulb Size |
|---|---|
| ECE standard (Europe & worldwide). Single-filament signalling bulb with BAY9s base. 12V, 21W. | H21W |