Buick LaCrosse Map Light Bulb Size

The Buick LaCrosse map light uses bulb sizes 12961 and 168 depending on the specific version of the vehicle. Information provided covers the range from 2005 through 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
2010-2016	12961
2005-2009	168

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 4.9W.	168

Other Locations

Additional Notes

The Buick LaCrosse map light bulb specification calls for two distinct bulb sizes across the 2005-2016 model years: the 168 for earlier models and the 12961 for later models.
The 12961 is a Philips part number designation for a miniature wedge bulb in the T10 form factor, rated at 12V and 5W, with a W2.1x9.5d base. The Buick LaCrosse uses this bulb for the map light across the 2010-2016 model years.
The 168 is an ANSI-standard designation recognized in the United States and Canada, also a T10 miniature wedge bulb, rated at 12V and 4.9W. It is specified for the 2005-2009 model years.
Both the 12961 and the 168 share the T10 miniature wedge form factor, meaning they are physically similar in shape and base type. However, the 12961 carries a W2.1x9.5d base specification under its Philips designation, while the 168 is defined under the ANSI standard system.
The wattage difference between the two bulbs is minimal: the 12961 is rated at 5W and the 168 at 4.9W. Both operate on a 12V circuit, consistent with standard automotive electrical systems.
Because the 12961 is a manufacturer part number rather than an ANSI industry code, sourcing it may be tied more closely to Philips product lines, whereas the 168 designation allows for broader cross-brand availability under the ANSI standardization framework.
The T10 wedge base is a common automotive bulb format used in low-current interior lighting applications such as map lights, courtesy lights, and instrument panel illumination. Its wedge-shaped base locks into the socket without a separate metal contact pin.
A bulb size change occurs between the 2009 and 2010 Buick LaCrosse model years, with the specification shifting from the 168 to the 12961. Substituting one for the other across this boundary without confirming socket and circuit compatibility is not advisable.