The Volkswagen GTI side marker utilizes a 12961 bulb size for the lighting components located on the exterior of the vehicle. Data for the specific bulb requirements covers the range from 2006 to 2009.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 12961 is the dominant bulb type across the Volkswagen GTI side marker specifications, appearing in both front and rear positions across multiple model years.
The 12961 is a Philips part number designating a T10 miniature wedge bulb with a W2.1x9.5d base, rated at 12V and 5W.
The T10 wedge base design of the 12961 requires no locking rotation to seat, as the wedge-shaped base is held in place by friction within the socket.
For the 2015-2018 Volkswagen GTI, the 12961 front side marker fitment is conditional, applying specifically to vehicles equipped with halogen capsule headlamps.
The 5008 follows the ANSI standard used in the United States and Canada, featuring a BA15s single-contact bayonet base, which is a twist-and-lock style mount distinct from the wedge base of the 12961.
The BA15s bayonet base of the 5008 and the W2.1x9.5d wedge base of the 12961 are physically incompatible socket types, meaning the two bulbs are not interchangeable despite both operating at 12V.
The 5008 is described as a lower wattage variant of the 1156, which means it shares the same BA15s base family but draws less power, making direct substitution with a standard 1156 a wattage mismatch.
The 2006 Volkswagen GTI rear side marker uses the 5008, while the 2007-2009 rear side marker position uses the 12961, indicating a socket type change between those model years that affects bulb selection.