My 1999 XK8 Vehicular Care manual shows that I should be using the NGKPFR5G-11E plug. The NGK site

NGK Partfinder for Cars & Light Commercial Vehicles

lists this plug for years ranging 03/00 - 02/02 and NGK PFR5G-13E for years ranging 09/98 –03/00. So why the conflict? I have also noticed that the NGK PFR5G-13E plug is readily available in the US and Canada while the NGKPFR5G-11E plug is UK order.

So can I use either? I'm confused but want to make sure I get the right plug if it matters. I haven't pulled a plug and looked to see what is actually in my XK8 but then who is to say that the installed plug is the "right" one anyway?

 

I can't remember what ones I runin the XJ8, but clubplug.ca has some decent prices. Rockauto is also a good source, see what they say.

 

The North American market was issued a TSB for the 1.3mm gap (NGK PFR5G-13E)

You can use the -11E and increase the gap for idle quality (or not).

Here is the old bulletin

bob gauff

 

Below are the gap specifications from Jaguar, where the difference is mainly the engine type (i.e. AJ26/AJ27 or newer).