The Jaguar XJ8 side marker requires a 12961 bulb size for proper illumination and function. Available information covers the span of time from 1998 through 2009 for the specified vehicle.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Jaguar XJ8 uses the 12961 bulb across all listed model years for both front and rear side marker positions, making it the sole bulb type referenced in these specifications.
The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor with a W2.1x9.5d base, operating at 12 volts and 5 watts.
The T10 designation refers to a tubular bulb approximately 10mm wide, and the W2.1x9.5d base describes a wedge-style base where the glass envelope itself acts as the retention mechanism rather than a metal cap.
At 5 watts, the 12961 is a low-output bulb suited to marker and position lighting functions rather than primary illumination.
The front side marker position on the Jaguar XJ8 uses the 12961 bulb across the 1998-2009 model year range.
The rear side marker position uses the same 12961 bulb, with specifications covering the 2001-2009 model year range.
The shared bulb type across both front and rear side marker positions means a single bulb specification applies to all listed side marker sockets on the vehicle.
The W2.1x9.5d wedge base is a standardized international base type, and the 12961 Philips part number represents one manufacturer's version of this widely used T10 wedge format.