Do spark plugs really need changing every 6000 miles ?

[Dodsy]

As my 450 is due a service I have been checking what needs doing. One thing on the service schedule that seems odd is that spark plugs are replaced at every service. Surely they dont need doing every 6000 miles ? I last had new plugs fitted 13 months and 4500 miles ago, is there any need to change them now ?

My 4.2l supercharged Jag needs new spark plugs every 100k miles hence the question.

[QBee]

The Rover V8 engine was originally created by Buick in the 1950s. It runs on cheap plugs. For best results they recommend you change them more often. Cost £ 20 a set.

I have no idea of the vintage of your Jaaaaaag engine, but my old 1990s super smooth 4 litre Lexus ran on iridium plugs, and the service schedule was every 60,000 miles. But they cost about £80 a set. I have just fitted NGK BPR6IEX plugs to my Chimaera and intend to change them every 30,000 miles. But they cost me about £65 for the set.

pays your money, takes your choice. I feel mine runs better on these, but it's only marginal.

[Dodsy]

Jag is an 07 Plate X350 XJR and runs on Iridium plugs. I had them changed at 90k and to be honest the ones that came out didnt look much different from the new ones going in.

I think I will give the more expensive plugs a try and just keep an eye on them.

[rev-erend]

As others have said - these plugs foul.

New plugs is the best performance / £££ improvement you can make but platinum plugs would be great (not sure if there is a listing) but cost something like £20 per plug.

[WOO5IE]

Hi Dodsy

I have just recently changed my XK 150 plugs which are NGK Iridium, scheduled for change at 100k or 10 years these cost me about £55 from a place in the states.£90 over here on EBay

I have also changed my Chim plugs to BPR6ES for ignition issues I.e got rid of the plug extenders and I got a box of 10 for £10 off EBay

A no brainier. At this price
They are a bit fiddly to get at but that's another story!!

[Dodsy]

WOO5IE said:

Hi Dodsy

I have just recently changed my XK 150 plugs which are NGK Iridium, scheduled for change at 100k or 10 years these cost me about £55 from a place in the states.£90 over here on EBay

I have also changed my Chim plugs to BPR6ES for ignition issues I.e got rid of the plug extenders and I got a box of 10 for £10 off EBay

A no brainier. At this price
They are a bit fiddly to get at but that's another story!!

Iridium NGKs for the Jag were £80 inc shipping from EuroCarParts, worth every penny although as I said the outgoing plugs didnt look particularly worn although I did change them 10k miles early.

TVR plugs I have decided to leave for now having only done 4.5k in the last 13 months just an oil and filter change this time around then new plugs next time.