Buick Encore GX Tail Light Bulb Size

The Buick Encore GX tail light requires bulb size 12961 or 7443 depending on the specific vehicle configuration. Data for the provided bulb sizes covers the range from 2020 to 2024.

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
2023-2024	12961
2021	12961
2020	7443

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961
ANSI standard (US & Canada). Dual-filament wedge bulb (T20). 12V, 21W/5W.	7443

Other Locations

Additional Notes

The 12961 is a miniature wedge bulb with a T10 form factor, a W2.1x9.5d base, and a 12V, 5W rating. It is designated by a Philips part number rather than an ANSI standard code.
The 7443 follows the ANSI standard used in the US and Canada. It is a dual-filament wedge bulb with a T20 form factor, rated at 12V with a 21W high filament and a 5W low filament, making it suitable for combined stop and tail light functions.
The Buick Encore GX uses the 12961 bulb for the tail lights across the 2021 and 2023-2024 model years.
The 2020 model year uses the 7443 bulb, which differs from the 12961 in both physical size and wattage. The T20 form factor of the 7443 is larger than the T10 of the 12961, and the two bulbs are not interchangeable.
The shift from a dual-filament 7443 in 2020 to a single-filament 12961 from 2021 onward reflects a change in the tail light assembly design between those model years.
Because the W2.1x9.5d base of the 12961 and the wedge base of the 7443 are physically distinct, substituting one for the other would result in an incompatible fit within the socket.