Spark plugs... Replace every 30,000 miles???

[RemarkLima]

Hey all,

Just a quiet moment at work before I head off and just checking a few things to sort on my car in the service manuals.

Anyway, came across the maintaince schedule, and in there it says for "normal" climates (I assume that\'s the UK, not like a desert or anything) you should replace the spark plugs every 30,000 miles (48,000 KM)... So is this just wishful thinking? Or are there different plugs that last this long? Or are we just changing them too often to mask another potential problem (running rich / HT leads / coils going bad etc...)?

Cheers,
Mark

[davehg]

i normally do mine every 3k but i run 10\'s and 11\'s

[Ricco_04]

I changed a set of mine after nearly 10,000 miles (all 9\'s) car wasn\'t running bad and new plugs really didn\'t make any noticeable difference.  I will usually change then every 6k.  I suppose it depends how much stick you give it - more rev\'s etc.

[trevtubby]

that seems like an awful lot of miles, even "normal" cars should change the plugs more than that? surely?

I change mine every 6k miles...basically, every other oil/filter change.

[FLAT4MATT]

Mine were shot after 6k but they\'re the greddy racing plugs... Apparently they should be changed about every 3-4k... Oh and they\'re about a hundred bloody quid!!!!

[Red and Single]

Similar to ricco, I changed a set after several thousand, maybe 8000, and it made sod all difference to the car. They looked tired, but it was running fine.

Mine had 10\'s and 9\'s in it, swapped to 9\'s all around without any detriment.

I only run low boost though (0.8 bar max) due too stock injectors, I think if you push the car harder (higher boost = more heat) they dont last as long for sure.

9\'s are absolutely dirt cheap if bought in quantity from the USA, just search on //www.rx7club.com for a decent supplier, they can be got for around £4 each landed IIRC

All the best :cheers

[gregmacd]

I don\'t remember the recommended plug change interval but I had the same set of plugs in my 200 for nearly 50,000 miles.

I didn\'t know you were supposed to change them regularly.

[RemarkLima]

Apparently they should be changed about every 3-4k... Oh and they\'re about a hundred bloody quid!!!!

That\'s what everyone has said... Except Mazda USA who say every 30,000 miles

And £100 for plugs??? What ones are you running?

I get 7\'s and 9\'s or 9\'s all round for about £40 + P&P

[FLAT4MATT]

That\'s what everyone has said... Except Mazda USA who say every 30,000 miles

And £100 for plugs??? What ones are you running?

I get 7\'s and 9\'s or 9\'s all round for about £40 + P&P

NGK / Greddy racing plugs like these http://www.rx7guru.com/rx7plugs.htm

[Red and Single]

NGK / Greddy racing plugs like these http://www.rx7guru.com/rx7plugs.htm

At the boost in your sig, you are running very similar setup to me and mine runs sweet on 9\'s all around !!

I\'d save your money if I was you mate

[FLAT4MATT]

Pip apparently had issues with a misfire high up the revs on standard plugs...