iridium plugs. do they make a difference

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Originally Posted by bobdoo
Back in '77, I had a Honda Civic. It had a tiny battery, and the conductor in the battery cables was about the thickness of a #2 Pencil *lead*.

(I found that out the hard way, -20f, no startee).

That's when I started clipping the side electrode shorter and pointier. (I also did the same on my RD350, which had a terrible weak spark).

That helped significantly with starting (the RD ran to redline in 5th gear. It wouldn't before that).

I think these new fine-wire designs are great, and will make some difference. Although the modern ignition systems are just so good...


All of the above (including the bit about the RD, but mine was a 400). The trick is that sparks like to jump off sharp points of metal. But combustion like to erode things to a rounded nature. Fine wire plugs will support at least a 10% wider gap with no more strain on the ignition system because they maintain that small spark initiation point. So put them in with a slightly bigger gap and get the benefits of larger ionization ball
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So i went to the store and bought some NGK iridium for the 2011 CRV. when i pulled the old plugs which had 108k on them i checked the gap. Suprisingly the gap was still at .44 as speced in the book. put them in and then drove it for a little. i could tell with my calibrated rear end that it was smoother and had more pickup.

it also cured what i thought was a slight misfire but never set off a CEL. i am probably going to change these every 60k just to be sure . thanks for all the info guys
 
If your car is 10 years old, what the manufacturer spec'd is obsolete. The times they are a-changin'. It's all about Iridium and moving to Ruthenium. Copper plugs are for old men.
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Originally Posted by Snagglefoot
If your car is 10 years old, what the manufacturer spec'd is obsolete. The times they are a-changin'. It's all about Iridium and moving to Ruthenium. Copper plugs are for old men.
smile.gif


How do you figure? If my cars 10yrs old why should I spend the extra money to go from platinum (OE spec) to the more expensive ruthinium, if a) I'm gonna sell it within 5yrs or b) the tranny/car may not last long enough (another 10yrs) to justify the added expense?

I actually stepped up to NGK iridium from OE spec platinum ONLY because I plan on giving this ride to my kids in a couple years so it's worth it to me to pay the added cost of iridium plugs...but if I were planning on selling/trading it in the next couple years I'd have put in the cheaper OE platinum plugs. (they'll still easily do 75k miles in this engine, barring fouling/heat problems)
 
Wow! Whats the Vehicle in question! Wait, I see it......Honda Civic.....that car, whatever you put in I t would be fine......What does the Owners Manual state?
 
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Originally Posted by BrocLuno
Originally Posted by bobdoo
Back in '77, I had a Honda Civic. It had a tiny battery, and the conductor in the battery cables was about the thickness of a #2 Pencil *lead*.

(I found that out the hard way, -20f, no startee).

That's when I started clipping the side electrode shorter and pointier. (I also did the same on my RD350, which had a terrible weak spark).

That helped significantly with starting (the RD ran to redline in 5th gear. It wouldn't before that).

I think these new fine-wire designs are great, and will make some difference. Although the modern ignition systems are just so good...


All of the above (including the bit about the RD, but mine was a 400). The trick is that sparks like to jump off sharp points of metal. But combustion like to erode things to a rounded nature. Fine wire plugs will support at least a 10% wider gap with no more strain on the ignition system because they maintain that small spark initiation point. So put them in with a slightly bigger gap and get the benefits of larger ionization ball
smile.gif



Good stuff. Thanks guys.
 
Originally Posted by Mad_Hatter
Originally Posted by Snagglefoot
If your car is 10 years old, what the manufacturer spec'd is obsolete. The times they are a-changin'. It's all about Iridium and moving to Ruthenium. Copper plugs are for old men.
smile.gif


How do you figure? If my cars 10yrs old why should I spend the extra money to go from platinum (OE spec) to the more expensive ruthinium, if a) I'm gonna sell it within 5yrs or b) the tranny/car may not last long enough (another 10yrs) to justify the added expense?

I actually stepped up to NGK iridium from OE spec platinum ONLY because I plan on giving this ride to my kids in a couple years so it's worth it to me to pay the added cost of iridium plugs...but if I were planning on selling/trading it in the next couple years I'd have put in the cheaper OE platinum plugs. (they'll still easily do 75k miles in this engine, barring fouling/heat problems)

Yep, there are always special situations.
 
It is about longevity, as already stated. For me, it depends on how hard the plugs are to get to and change. The more difficult, the more I'll spend to reduce the number of times I'll have to change them.
 
Mazda Skyactiv engines specify iridium/platinum plugs (iridium center electrode with platinum disc on ground strap). A TSB (E006/12) states that using anything less will result in knock and CEL. For my 2012 Mazda3 the specified plug is NGK 94124. They are $30 each from Mazda, $10 each on Rock Auto. Where do you think I bought them when it came time to replace?

I thought this might be useful info for Mazda owners.
 
Originally Posted by NO2
Ruthenium plugs seem to be the most economical choice. According to the press releases they last 20-40% longer than iridium.


Double platinum, let alone iridium, are already good for 100k. Not really sure how Ruthenium will be better unless you are trying to hit 200k on them. And I can count on one hand the people that keep their cars 300k, since most factory plugs are good till the 100k service.
 
Many people with vehicles that spec copper plugs have changed to iridium or platinum simply because the plugs are difficult to access and they want to change them less. The iridium/platinum plugs simply keep the proper gap longer, and so can stay in the engine longer. So no, there is no benefit other than longevity. Copper does conduct better but most people will never notice any change in performance.
 
Originally Posted by WhyMe
performance wise? besides the long life, are there any other benefits of running an iridium plug? could i pick up performance by using a platinum or copper plug in my vehicles?


For the same tip size probably not. However, with a more durable material they can also make the center electrode smaller, and therefore reduce misfires and lower the needed firing voltage, this always help.

You can make a typical 1.1mm platinum tip, but not 0.7mm like Iridium.
 
prolly less performance with cheap $2 copper plugs but due difficulty of changing the harder longer lasting poor conducting exotic metals are popular, surely not their price but paying to install difficult plugs iridum makes dollars + sense!
 
Don't take my word. Put iridium plugs in your lawn mower and see it start easier and use less gas.
 
While the iridium and platinum plugs last longer, they don't provide any benefit for power nor mpg. My engines run just the same on cheap $3 conventional plugs. I find myself having to pull the iridium plugs every 30-40k miles to reset the gap anyway so I switched to conventional plugs. Our race engines run on a $3 conventional NGK plugs.
 
I liked the fine tip design for the Denso TT plugs and have installed them quite often up until now, but the set of 4 Denso Iridium TT that I installed 2.5 years ago in a 2011 Kia Soul 2.0L were COMPLETELY worn out after 50k miles, so please be aware that these fine tip precious metal plugs may perform well when new, but they are definitely susceptible to accelerated erosion due to various factors. One reason in this case may be due to this engine having only 2 ignition coils, which means that the plugs fire twice as often as COP design due to a wasted spark on every exhaust stroke. I noted on cylinders 1 and 4 that the center electrode had worn down to the ceramic while the ground side fine tips still looked good. However, on cylinders 2 and 3, the center electrode still had a recognizable point, and instead the ground electrode fine tip was completely worn to nothing. The engine was misfiring whenever accelerated just beyond normal acceleration. I replaced these completely worn plugs with the original design NGK double platinum LASERS and a new set of quality wires and now it runs like new again. When I replaced the original plugs they were not really worn and were only replaced as a normal maintenance item. The car was actually still running well.

I had fully expected to get a full 100k miles from the Denso Iridium TT's since they are supposedly high quality iridium, and iridium plugs are usually considered long life. But now I am seeing that some iridium designs are WAY LESS durable than others. If I had decided to run the Denso Iridium TT's again in this engine, they would need replaced again in no more than 40,000 miles. The car currently has 163,000 miles and the originals were replaced around 110k miles.

I contacted Denso Technical support about my experience and the guy I talked to was totally uninterested in seeing or discussing my results with their iridium TT plugs. I was as always very polite, but his final comment before hanging up on me was "good luck". Apparently "good luck" is what is needed when using their products. I will move to another brand, thank you.
 
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