I am looking at NGK spark plugs for my Dakota. The stock factory recommended plug gap is .040". Most plugs on the Napa website - Champion, Autolite, etc all say they are gapped at the factory .040". The NGK plugs say they come gapped at .044". I have researched online and on the NGK website. I can't find a reason why NGK specs a higher gap other than they say their spark kernel is larger and is supposed to put more spark in the air-fuel mix. Does anyone here have any other info on it? And does the slight gap difference really matter or provide any benefit? I have a stock ignition and factory distributor on my truck. No MSD, Accel, Mallory etc. I burn regular 87 octane gas. Thanks for any info on this.
NGK plug gap
- Thread starter Jimmy9190
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Are these standard plugs or platinum/iridium/unobtainium?
Plain old standard copper core NGK's. Stock heat range. $2.69 each at Napa.
I would buy the best Iridium plugs you can buy . Then you are set for the next 75-100k miles. You can buy a set of 6 on ebay for $40-$45/ set of 6 plugs. Or try Rock Auto. Champion makes a quality plug as well as the NGK's IMO. FWIW--Oldtommy
Jimmy, maybe this will shed some light. I have an '05 Caravan 4 cyl. that Chrysler issued a TSB on in 2004 for a spark plug change (TSB 08-008-04).
The TSB lists both copper Champion and NGK plugs (LZTR4A-11) to be gapped at the "new" plug gap of .040". The NGK site still lists my application at .044.
I'm following Chrysler's TSB recommendation. But, you might want to check with NGK to see if they have a reason, or they just missed changing with Chrysler's change.
My original plug gap recommendation was .050. I sent a ? (for my van) to their tech. dept. for an answer about the gap difference.
The TSB lists both copper Champion and NGK plugs (LZTR4A-11) to be gapped at the "new" plug gap of .040". The NGK site still lists my application at .044.
I'm following Chrysler's TSB recommendation. But, you might want to check with NGK to see if they have a reason, or they just missed changing with Chrysler's change.
My original plug gap recommendation was .050. I sent a ? (for my van) to their tech. dept. for an answer about the gap difference.
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.039-.044" (1-1.1mm) is the std gap range for most denso asian application. You get higher current spark at the larger gap. Most folks start at the low end and the gap will erode through the parts usefull life. If it was me id have a set of Champions or plain jane copper Autolites or plain jane Cu bosch or plain jane Denso in there (if they are easy to service) - OTW install double platinum Nippon Denso. I dont think you should use Ir plugs on a neg firing (dual ended resonant waste spark coil system) they are more to reduce misfire on the weak denso COP ignition systems. IDK what dodge is using on this V6.
Thanks for the replies. I do not have a coil on plug ignition. It's old school distributor, rotor button, 6 plug wires and 6 plugs. OEM plug is a copper core Champion. Dodge does not recommend the use of platinum, iridium, plutonium or any other plug. Most Dakota owners do not like Champion and will not use Champion replacement plugs. Some use NGK and they work very well. A lot of Dakota owners use Autolite plugs. I have been using Autolite too, but I do not want to use them any more. The Autolite plug for my truck is now being made in Mexico, some other Autolite plugs are now made in China and I hear there are lots of quality issues with Autolite now. No Autolites are made here in the USA. NGK, OTOH is said to be a very high quality plug and is made in West Virginia. I would rather buy the NGK but am very curious about this difference in the gap.
If you use the platinum/iridium hybrids I'm pretty sure the larger gap is due to them being easier to jump with this plug design.
NGK is a great choice. I'd choose my plug by how long I wanted to run them.
NGK is a great choice. I'd choose my plug by how long I wanted to run them.
I'd go with OEM Champons gapped to the latest .040 spec
NGK on the GC, and gapped to the vehicle specs, rather than the manufacturer's factory setting; have always had no problems whatsoever. I like the $2 per plug cost. I've tried the fancy plugs, but since they're $6-8 each and last the same length of time as the NGK, there's no sense getting them.
The advice to use the OEM Champion plug isn't bad, either.
The advice to use the OEM Champion plug isn't bad, either.
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Wow, NGK answered my question via e-mail in less than one hour.
Their response (for my application described above):
"The spec is actually 1.0-1.1mm which is equivalent to .040-.044" and anywhere within this range is acceptable. The LZTR4A-11 also come factory set to 1.1mm (.044") with a tolerance up to -.004" Hope this helps, thank you."
Their response (for my application described above):
"The spec is actually 1.0-1.1mm which is equivalent to .040-.044" and anywhere within this range is acceptable. The LZTR4A-11 also come factory set to 1.1mm (.044") with a tolerance up to -.004" Hope this helps, thank you."
Originally Posted By: doitmyself
Jimmy, maybe this will shed some light. I have an '05 Caravan 4 cyl. that Chrysler issued a TSB on in 2004 for a spark plug change (TSB 08-008-04).
The TSB lists both copper Champion and NGK plugs (LZTR4A-11) to be gapped at the "new" plug gap of .040". ....
Is this the 2.4liter that used to burn up plugs in less than 10k? That's what we have in our Wrangler and the TSB is right on; we've had good luck with the Champions. RE16MC (oof the top of my head)
Jimmy, maybe this will shed some light. I have an '05 Caravan 4 cyl. that Chrysler issued a TSB on in 2004 for a spark plug change (TSB 08-008-04).
The TSB lists both copper Champion and NGK plugs (LZTR4A-11) to be gapped at the "new" plug gap of .040". ....
Is this the 2.4liter that used to burn up plugs in less than 10k? That's what we have in our Wrangler and the TSB is right on; we've had good luck with the Champions. RE16MC (oof the top of my head)
Originally Posted By: Kuato
Is this the 2.4liter that used to burn up plugs in less than 10k? That's what we have in our Wrangler and the TSB is right on; we've had good luck with the Champions. RE16MC (oof the top of my head)
Yes, but I "think" there was another TSB for that issue (maybe?). My TSB says it was made to address "cold engine carbon fouling".
To the OP, the NGK FAQ at their site also says to consult the mfg. spec. regarding gaps, somewhat implying to follow the mfg. specs.. And, my e-mail answer did not imply that they set them a bit higher for any performance reason (I asked about this). Just my opinion.
Is this the 2.4liter that used to burn up plugs in less than 10k? That's what we have in our Wrangler and the TSB is right on; we've had good luck with the Champions. RE16MC (oof the top of my head)
Yes, but I "think" there was another TSB for that issue (maybe?). My TSB says it was made to address "cold engine carbon fouling".
To the OP, the NGK FAQ at their site also says to consult the mfg. spec. regarding gaps, somewhat implying to follow the mfg. specs.. And, my e-mail answer did not imply that they set them a bit higher for any performance reason (I asked about this). Just my opinion.
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Thanks for the help. I will just use the NGK plugs and gap at the factory .040". It really is splitting hairs worrying about .004" of gap difference anyway. I found a few posts about it online, some had left the gap at .044, some had changed it back to .040", but no one had any problems and there was no performance/idle/MPG difference reported with either one.
Thanks for the help here.
Thanks for the help here.
FWIW, here's a link to a chart that decodes NGK's numbering system.
http://www.ngk.com/sparkplug411_ngk.asp
http://www.ngk.com/sparkplug411_ngk.asp
Since you should check the gap on any new plug [and inspect all sorts of other things], why not just gap them to .040"?
Unless you are truly lower than average, this is easy and safe.
Unless you are truly lower than average, this is easy and safe.
Originally Posted By: mechtech2
Since you should check the gap on any new plug [and inspect all sorts of other things], why not just gap them to .040"?
Unless you are truly lower than average, this is easy and safe.
Confirming the gap should be SOP.
I use a tool like this:
http://www.collectingsnapon.com/pliers/SparkPlugGapping.html
Wire gauges should be used on plugs, but I find the pliers type quick and easy.
From personal experience, if you're going to get a pliers type gap tool, look for the ones with individual thickness blades; avoid the tapered disk kind like the Jacobs. The Jacobs tool is rather useless, IMO. It's hard to tell what part (thickness) of the tapered disk your sticking in between the electrodes.
Since you should check the gap on any new plug [and inspect all sorts of other things], why not just gap them to .040"?
Unless you are truly lower than average, this is easy and safe.
Confirming the gap should be SOP.
I use a tool like this:
http://www.collectingsnapon.com/pliers/SparkPlugGapping.html
Wire gauges should be used on plugs, but I find the pliers type quick and easy.
From personal experience, if you're going to get a pliers type gap tool, look for the ones with individual thickness blades; avoid the tapered disk kind like the Jacobs. The Jacobs tool is rather useless, IMO. It's hard to tell what part (thickness) of the tapered disk your sticking in between the electrodes.
My new NGK's were all spot on .044" right out of the box. I re-gapped them to .040" and put them in and did the rest of my tune-up today. All I can say is I am very impressed with the NGK's. I know they are brand new but there is a night and day difference between the NGK's and the Autolites I was using before. Truck starts easier and a little faster, it idles smoother, and it seems to have a little more power on the butt-dyno. I hope I get at least a little better MPG on these new plugs. For some reason 3 out of 6 ofthe Autolites had increased their gaps to about .045.
I installed new Napa Belden wires, and a new Napa distributor cap and rotor button that have brass contacts today too. I also removed my throttle body and cleaned it and my Idle Air Control Valve, and lubricated all the pivot points on the throttle body. Truck runs very well now.
I installed new Napa Belden wires, and a new Napa distributor cap and rotor button that have brass contacts today too. I also removed my throttle body and cleaned it and my Idle Air Control Valve, and lubricated all the pivot points on the throttle body. Truck runs very well now.
No, I am not saying it runs better just because I used NGK plugs. But they are a part of the reason why it is running better. So are the better-quality distributor cap and rotor button. Their brass contacts last longer and get a better spark and a bit more voltage to the plugs. New plug wires help too, but there was probably nothing wrong with my old wires. I change them out every other year and for 26 bucks it's cheap insurance. 3 out of the 6 Autolites I removed had increased their gap to .045 or a little higher. Maybe that had something to do with it too.
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