Spark plug recommendations for 6.0L XJR-S

Since I have time on my hands, after 70k miles, I should perhaps consider new plugs and leads for my XJR-S? i just pulled a NGK BR7EFS out and it doesn’t look too bad, gap looks a bit big at 0.035" but it, and its 11 brethren, seems to have been OK for 15 years up to now. Should I save my pennies and just clean and re-gap them? Any point changing the plug leads just because they are old?

If the center electrode isn’t too rounded, just regap them, and they’ll be fine.

the BR7EFS are cheap, if you’re able to get some during lock down, why would you not change them ?
not sure they’re the right ones for the RS, though : I thought those needed slightly different model

I’d say way overdue. Please do make sure the gap is 0.025", not 0.035"

The XJR-S specific manual for 1992 specifies the no longer available Champion RS6YCC. Online cross reference guides throw themselves into a spin over this. Any ideas?

I’ve no affiliation with him but, you could try contacting Vince Franklin (XJR-S & TWR Owners Group) on FB as I seem to remember him having a set for sale not too long ago.


Oh, come on. Plenty:

Champion RS6YCC replacement spark plugs

AC Delco C41CLTS

Autolite 102

Beru 14K-5DU

Bosch H56

Bosch HR5DC

Brisk G12YC

Brisk GR12YC

Champion EON3

Champion EON3286

Champion EON3287

Denso 5040

Denso 5327

Denso IT22

Denso T22EP-U

Denso T22EPU

Eyquem 800LJS

Eyquem 803LJSP

Eyquem 805LJSP

Iskra FER75P

Lodge HLT

Magneti Marelli 062110340312

Magneti Marelli T8LC

Motorcraft AGF12C

Splitfire SF10B

Unipart GSP381

Valeo 246883

Valeo C64HP

Now, Denso 5040, a readily available nickel-plug that retails in the US for less than $1.5/ea. can be found cross-listed with:

Yeah, I found that website too. When I do parts cross referencing, I like to be thorough - I’ve been caught out twice before with XJ12 rear brake shoes that are wrongly cross referenced to a Citroen. So picking on your example of the Denso 5040, the backwards reference on that website is to 13 different Champion plugs, none of which are the same Champion ENO part numbers that your search came up with as alternatives to RS6YCC. So that all looks pretty bogus.

If I wanted spark plugs for my grandma’s 2013, 1.8L Toyota Corolla then sure, a generic replacement would be absolutely fine. But I don’t really trust those random parts (anyone ever heard of Eyquem spark plugs before?) as true replacements for a specific plug, on a high spec engine.

Thank you for implying that I am not thorough (btw, if you look up some of my posts, you’ll see that I have corrected many cross-listed errors in previous posts, the pads and shoes for the rear outboard brakes too)

Mine being a “pedestrian” 6.0L, not the high spec TWR 6.0L variant you’re speaking of is more than happy with NGK BR7EF, or the hotter BR6EF.

The Champions Jaguar TWR recommends appear to be obsolete in year 2020, sadly.