BMW M3 Dome Light Bulb Size

The BMW M3 dome light utilizes bulb sizes 12961, DE3423, and 6411 depending on the specific version of the internal illumination component. Available data for the lighting specifications spans from 1988 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	12961
2012-2013	12961
2008-2010	12961
2001-2006	DE3423
1999	6411
1998	DE3423
1995-1997	6411
1988-1991	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 M3 dome light specifications reference three distinct bulb types across model years: the 12961, DE3423, and 6411.
The 12961 is a Philips part number designating a T10 miniature wedge bulb with a W2.1x9.5d base, rated at 12V and 5W. It fits the BMW M3 for model years 2008-2018, with the exception of 2011, 2014, and 2016 being absent from that range.
The W2.1x9.5d base on the 12961 is a wedge-type connection, meaning the bulb is held in place by tension rather than a twist-lock or bayonet mechanism.
The DE3423 is an ANSI-standard festoon bulb with a 41mm length and end-cap contacts, rated at 12V. It is specified for the BMW M3 across model years 2001-2006, as well as 1998.
The 6411 is also an ANSI-standard festoon bulb, rated at 12V and 5W, but with a 36mm length and an SV8.5 base. It is specified for model years 1988-1991 and 1995-1997, as well as 1999.
Although both the DE3423 and 6411 are festoon-style bulbs operating at 12V, their lengths differ: 41mm versus 36mm. These two types are not interchangeable due to this size difference.
The 12961 wedge bulb and the festoon-type DE3423 and 6411 use fundamentally different base designs, making cross-substitution between the wedge and festoon types physically incompatible in the dome light socket.
The year 1998 uses the DE3423, while 1997 and 1999 both use the 6411, indicating that adjacent model years of the BMW M3 do not necessarily share the same dome light bulb fitment.