The Jaguar XK front inner turn signal uses 3357NA or 3457NA bulb size, while front outer and rear turn signals require PY21W or 12496 bulb size. The replacement chart covers 2007 to 2015 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 3457NA bulb is the most frequently specified turn signal bulb across the Jaguar XK's listed positions and years. It appears in the Front Inner Turn Signal for 2007-2008 and across all six Front Turn Signal positions from 2010-2015.
The 3457NA is a dual-filament T25 wedge bulb rated at 12V with a 27W main filament and a 7W secondary filament. The natural amber glass produces the required amber signal color without relying on a tinted lens or colored coating.
The 3357NA, used in the 2009 Front Inner Turn Signal, shares the same T25 wedge form factor and 12V/27W rating as the 3457NA but is a single-filament bulb. The two types are not interchangeable where dual-filament operation is required.
Both the 3357NA and 3457NA conform to ANSI standards, which govern bulb specifications primarily in the United States and Canada. The "NA" suffix on both designations denotes the natural amber glass envelope.
The PY21W is the second most prevalent bulb type in these specifications, covering the Front Outer Turn Signal and Rear Turn Signal positions for 2010-2015, as well as the 2007 Rear Turn Signal.
The PY21W operates on the ECE standard used in Europe and worldwide markets. It uses a BAU15s bayonet base, which has offset pins to prevent incorrect installation. This base is not compatible with the BA15s base found on non-amber variants of the 21W family.
The PY21W is rated at 12V and 21W, making it lower in wattage than the 3457NA's primary filament. The amber color in the PY21W is produced by the glass envelope itself rather than by a lens filter.
The 12496 is a Philips/Osram part number rather than an ANSI or ECE standard designation. It is rated at 12V and is listed for the Rear Turn Signal on the 2008-2009 Jaguar XK, where other model years in the same position use the PY21W.
The 2007 Rear Turn Signal uses the PY21W, while the 2008-2009 Rear Turn Signal uses the 12496. This means the rear turn signal bulb type is not consistent across the three earliest model years in the specifications.
The Front Inner Turn Signal position exists only for 2007-2009, with the 3457NA used in 2007-2008 and the 3357NA in 2009. From 2010 onward, the specifications list a Front Turn Signal position rather than a Front Inner Turn Signal, and that position uses the 3457NA throughout 2010-2015.