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Discussion Starter · #1 ·
I just hit 10k on my 17 Focus ST and I know the general consensus here is that these cars eat spark plugs for lunch. So Im just wondering how often do you guys change them? 10k,15k,20k, etc. I'm not experiencing any issues I just got to thinking about it after hitting 10k. Thanks!
 

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Discussion Starter · #2 ·
Follow up question. If everything seems to be running smooth and good should I at the very least check gap? Maybe every other oil change?
 

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I just hit 10k on my 17 Focus ST and I know the general consensus here is that these cars eat spark plugs for lunch. So Im just wondering how often do you guys change them? 10k,15k,20k, etc. I'm not experiencing any issues I just got to thinking about it after hitting 10k. Thanks!
Ford says something crazy like 100k, but general consensus is that they are cheap. Just check the gap on them EVERY OIL CHANGE or maybe every other if you'd rather, and if 20k miles rolls off and they are rough looking, order more. Cheap and easy insurance.

Edit: I replied as you typed your follow up question, but yes. Always check gap. Our car ungaps them very easily.
 

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Discussion Starter · #4 ·
Ford says something crazy like 100k, but general consensus is that they are cheap. Just check the gap on them EVERY OIL CHANGE or maybe every other if you'd rather, and if 20k miles rolls off and they are rough looking, order more. Cheap and easy insurance.

Edit: I replied as you typed your follow up question, but yes. Always check gap. Our car ungaps them very easily.
Good to know! Im not very rough on the car so mine probably are not that bad Ill check them next oil change. Or if I end up doing my intercooler install this weekend I will check them then
 

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Good to know! Im not very rough on the car so mine probably are not that bad Ill check them next oil change. Or if I end up doing my intercooler install this weekend I will check them then
Yeah most of us find we need adjustments after like 10-15k every time we check. Mine are way past due to be checked and I guarantee they need gapped. Idle and accel is starting to feel a little rough.
 

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Or you can be 100000% insane like myself and not replace or check gap for 40,000 miles ... lol
 

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Or you can be 100000% insane like myself and not replace or check gap for 40,000 miles ... lol
LMAO I thought I was bad. It's been like 20k now already since I checked so they're f__ked I guarantee it. They're one step colder too and tuned for .026 so it'll be night and day probably when I regap them.
 

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I check every 15k or so, they are always "within spec" but I regap to .26 on NGK step colder.

Gapping them every oil change is a little silly but whatever can't hurt as long as you do it right, if it helps you sleep at night do it. I am sure you will find that it is totally unnecessary and honestly if you have to regap every oil change something is wrong (based on 5k oil change).

I installed new plugs at 40k and checked them at 55k for my last oil change... didn't have to regap and felt like I totally wasted my time checking them, piece of mind to check them but completely wasted otherwise.
 

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LMAO I thought I was bad. It's been like 20k now already since I checked so they're f__ked I guarantee it. They're one step colder too and tuned for .026 so it'll be night and day probably when I regap them.
I know the stock plugs are horrible at moving gap, but after 20k on my NGK step colder plugs they moved 0%. Others have reported this too. Not sure about the Denso's.
 
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I know the stock plugs are horrible at moving gap, but after 20k on my NGK step colder plugs they moved 0%. Others have reported this too. Not sure about the Denso's.
same experience... I highly recommend the NGK step cooler no matter what, stock, tuned etc. get them and they will last longer, stay truer and run better
 

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same experience... I highly recommend the NGK step cooler no matter what, stock, tuned etc. get them and they will last longer, stay truer and run better
Yeah i have to throw mine in this week.. gapped at .026 :)
 
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I just pulled my originals out @ 44k to go 1 set colder.

new ones were gapped at .026 and all of the old ones were between .032 and .034.

Checking your plugs every oil change would definitely be a waste of time. As mentioned already, if your gap is moving enough to have to reap them after 5k, then something is wrong...

Maybe worth the peace of mind if you are really built and pushing it hard or have a lot of track days. But definitely over kill for 95% of owners.

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Pulled my Denso ITV22's after about 15k miles and one was ok. Others were .30, .39, and .40. That should give you some indication as to how often it needs done. I misfired 3 times on what felt like the same cylinder which made me pull them and check. Was getting some pretty bad ignition corrections on the AP on a couple cylinders, but running great now.
 

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Pulled my Denso ITV22's after about 15k miles and one was ok. Others were .30, .39, and .40. That should give you some indication as to how often it needs done. I misfired 3 times on what felt like the same cylinder which made me pull them and check. Was getting some pretty bad ignition corrections on the AP on a couple cylinders, but running great now.
I've having my buddy who's a mechanic change my oil in a week and I think I'll just have him check them out for me while I'm at it. Just don't have the time/place to change this stuff myself anymore, sucks.
 

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I've checked my plugs 2-3 times in the 5+ years that I've owned the car. My car has just over 100,000km. The last time I checked the plugs was over a year ago and they appeared to be in decent condition and the gaps were all relatively good.

I can't argue with the merits of fastidiously checking the plugs but I wanted to give some comfort to the people who never do.
 

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I've checked my plugs 2-3 times in the 5+ years that I've owned the car. My car has just over 100,000km. The last time I checked the plugs was over a year ago and they appeared to be in decent condition and the gaps were all relatively good.

I can't argue with the merits of fastidiously checking the plugs but I wanted to give some comfort to the people who never do.
That car wasn't a Ford Focus ST though, which chews through plugs ridiculously. I don't mind since they are cheap though.
 
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