BMW 328i Dome Light Bulb Size

The BMW 328i dome light uses bulb sizes 12961, DE3423, and 6411 depending on the specific version of the vehicle. Data for the lighting components covers the period from 1996 to 2016.

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
2014-2016	12961
1999-2000	DE3423
1996-1998	6411

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V.	DE3423
ANSI standard (US & Canada). Festoon bulb, 36mm length, SV8.5 base. 12V, 5W.	6411

Other Locations

Additional Notes

The BMW 328i dome light specifications cover model years 1996-2000 and 2014-2016, with three distinct bulb types used across those years.
The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor, fitted with a W2.1x9.5d base and rated at 12V, 5W. It is specified for the BMW 328i (2014-2016) dome light position.
The T10 wedge base design means the bulb is retained by friction rather than a bayonet or screw mechanism, which is a common trait of low-wattage interior lighting applications.
The DE3423 is an ANSI-standard festoon bulb rated at 12V, with a 41mm length and end-cap contacts. It is specified for the 1999-2000 model years.
The 6411 is also an ANSI-standard festoon bulb, rated at 12V and 5W, with a 36mm length and an SV8.5 base. It is specified for the 1996-1998 model years.
Both the DE3423 and the 6411 are festoon-style bulbs, meaning they seat between two spring-loaded end contacts inside the fixture. However, their lengths differ at 41mm and 36mm respectively, making them non-interchangeable despite sharing the same contact style.
The transition from the 6411 to the DE3423 between the 1998 and 1999 model years reflects a change in the required festoon length, from 36mm to 41mm.
The transition from festoon-type bulbs to the T10 wedge type between the 2000 and 2014 model years indicates a change in the dome light socket design across those generations of the 328i.
The ANSI designation on both the DE3423 and the 6411 indicates these are standardized bulb codes recognized across the United States and Canada, meaning equivalent bulbs from multiple manufacturers are available under the same designation.
All three bulb types across the specifications share a 12V operating voltage, consistent with the standard electrical system voltage of passenger vehicles.