Does anyone know how to determine the specific spark plug gap for a given jag? I can't find a repair manual for my 98 XJR, nor any help on the web for this issue. The guy at Autozone looked it up, said .04 - the NGK website said .03, but then .052 for the "OE", the autozone website said ".031", and the Denso website said .04. I'm lost, and I really don't trust that theses spark plugs (NGK iridium IX) are pre-gapped properly.
Any help would be much appreciated.

 

Here is what the JTIS has:

1.2 - 1.3 mm (0.047 - 0.051 in )

 

we always set at .048 and never have problems.

 

Nice to know Jagtech

Cheers

Jim