The Jaguar XJ12 side marker requires a bulb size of 12961 for proper installation and function. Data for the specified lighting component covers the range from 1995 to 1996.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Jaguar XJ12 uses two distinct bulb types across its side marker positions: the 12961 and the 1895, each belonging to different standardization systems and carrying different electrical ratings.
The 1895 is an ANSI-standardized bulb recognized in the US and Canada, while the 12961 is a Philips part number designation, reflecting a manufacturer-specific classification rather than a universal industry standard.
The 1895 bulb is a T5 miniature wedge type rated at 12V and 0.9W, making it among the lower-wattage bulbs used in automotive marker applications.
The 12961 bulb is a T10 miniature wedge type with a W2.1x9.5d base, rated at 12V and 5W, which represents a notably higher wattage output compared to the 1895.
The T10 and T5 designations refer to the bulb's tubular envelope width in units of one-eighth of an inch, meaning the T10 is 10/8 inch wide and the T5 is 5/8 inch wide. These two sizes are not interchangeable.
The W2.1x9.5d base on the 12961 is a wedge-type base where the contact pins are part of the glass envelope itself, a common construction in modern miniature automotive bulbs.
For the Jaguar XJ12, the front side marker on 1994-1996 models uses the 12961 bulb, while the front side marker on 1973-1977 models uses the 1895 bulb, indicating a specification change between those production periods.
The rear side marker position on the XJ12 uses the 1895 bulb exclusively across the 1973-1977 model years listed in the specifications.
Because the 12961 and 1895 differ in both physical size and base type, substituting one for the other in any given socket would not constitute a compatible fitment.
The 1895 bulb serves both the front and rear side marker positions on 1973-1977 XJ12 models, meaning a single bulb type covers all side marker sockets on those vehicles.