I have recently purchased a 4.2 Supercharged X350 XJR and now I would like to do some stage 0 maintenance. The car has 102k miles. I was looking over this forum and I am not sure which spark plugs are OEM specified for my XJR?

I have found two different part nubers:

Platinum NGK PFR5G-11
&
Iridium NGK IFR5N-10

Not sure which one are correct?

 

Iridium NGK IFR5N-10

 

+1 same as for my STR

 

Welcome to the forum Volvej,

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

I changed mine at 100,000 with the "equivalent" Bosch Iridium plugs. Bad move.

I managed to get worse mpg figures than with my original plugs. So changed back to Iridium NGK IFR5N-10 with mpg back up to what it should be.

Also have found that my mpg can vary substantially with where I by 93 Octane.

Local grocery store 93 Octane fairs much worse in my car than 93 Octane from Shell which is where I try and get gas all the time if I can.

 

If I ordered OEM spark plugs from the nearest Jaguar dealer, what brand would they be? 06 XJR.

Would they really be the NGK Iridium IFR5N-10 ?

As an aside, is there a good Jag parts lookup site that you guys use?

 

Call them and ask them. However I rather think you will pay more for them from a dealer.

 

I was hoping someone here would know. I don't want to call / email for a quote and ask if they're NGK if someone here has already bought OEM plugs and they are. I don't want to waste their time.

 

It depends on year and supply at time of manufacture. My 04 actually came with Motorcraft Iridium. NGK or Denso Iridium is what you are looking for. Both are excellent choices. NGK is my personal preference. Denso made all the electronics of the system though. Jaguar's OE is vended out and the porcelain is marked with the Jaguar part number.

 

I've just bought 8 genuine spark plugs from Jaguar for my XJR
They are part number: C2A1535 and they are NGK "IR" IFR5N 10

Hope this helps

 

Awesome that's exactly what I was looking for!

 

I e-mailed the dealer. They wouldn't give me the part number but did tell me they have the plugs in stock and they're $27 each (Canadian). I found 'em online for $12 US so I guess it's off to RockAuto / Amazon I go...

 

For what it's worth I found a PDF copy of the factory 2004 XJ service manual on this site. It specifies the NGK Iridium plugs.