Do iridium spark plugs not last long?

[The motor guy]

Didn't they start making spark plugs designed to make it to 100k? I don't think these iridiums plugs are very good. Had the same issue on the boat that I had on the side by side. Stumbling at lower rpm, nor firing on a certain cylinder. New plugs fixed it

 

[JoelB]

Iridium plugs are very long lasting. Maybe look at a problem elsewhere.

 

[Urshurak776]

Some, such as the NGK Iridium IX variety, are only good for 50-75K. Most are good for 100K, but check manufacturer for whatever plug you're using.

 

[Davejam]

NGK says Iridium IX 40-50k, NGK Laser Iridium 80-100K.
So, it can depend significantly. But you can probably get more than either figure if no other issues are present.

 

[Jimmy_Russells]

100k was a common thing for engines maybe 12-15 years ago. Now it's more like 60k when you consider most everything is turbocharged and GDI and some engines are firing the plug more than once per cycle also.

 

[tcp71]

The IX version is supposed to be more performance oriented at the expense of longevity. The lazer version is for longevity. Make sure you get the lazer version, but some applications work best with copper or platinum.

 

[jayjr1105]

I have Denso Iridium TT's in the Honda now for 100K. I think they are only rated for 75K but it's still running well. I plan on swapping them out soon.

Edit: nevermind, they are rated for 100K

 

[kschachn]

Didn't they start making spark plugs designed to make it to 100k? I don't think these iridiums plugs are very good. Had the same issue on the boat that I had on the side by side. Stumbling at lower rpm, nor firing on a certain cylinder. New plugs fixed it

I have run those plugs to 100K several times in all my vehicles and so far they look great when removed. You may have other issues.

 

[tcp71]

Our sienna is at 90k miles on the original plugs. The replacement interval is 120k miles but they are known to go 200k miles without issue (port injection/no turbo/low power output engine) in a lot of cases. I suspect ours will go to the recycler with original plugs.

 

[Ronn]

Didn't they start making spark plugs designed to make it to 100k? I don't think these iridiums plugs are very good. Had the same issue on the boat that I had on the side by side. Stumbling at lower rpm, nor firing on a certain cylinder. New plugs fixed it

I ran OEM Iridium in Hyundai Sonata GDI for 123K miles and they still ran well when I swapped them out.

 

[97prizm]

100k was a common thing for engines maybe 12-15 years ago. Now it's more like 60k when you consider most everything is turbocharged and GDI and some engines are firing the plug more than once per cycle also.

Yeah. I saw an article where Mercedes and maybe a couple others would fire the spark plug 5 times to eek out the best flame kernel and the most even combustion

 

[vavavroom]

Didn't they start making spark plugs designed to make it to 100k?

In what application? Generally speaking, in high-performance applications, iridium plugs outlast ruthenium plugs but in non-performance applications ruthenium will outlast iridium plugs. Both, iridium and ruthenium, are in the platinum group with slightly different properties. Whether standard platinum, iridium, or ruthenium is the optimal choice depends on the application and acceptable tradeoffs.

I don't think these iridiums plugs are very good.

Not all are created equal. Manufacturers may have more than one line of platinum, iridium, or whatnot plugs that vary in service life and price.

Had the same issue on the boat that I had on the side by side. Stumbling at lower rpm, nor firing on a certain cylinder. New plugs fixed it

How long did the spark plugs last before you felt firing problems?

 

[The motor guy]

In what application? Generally speaking, , In high-performance applications, iridium plugs outlast ruthenium plugs but in non-performance applications ruthenium will outlast iridium plugs. Both, iridium and ruthenium, are in the platinum group with slightly different properties. Whether standard platinum, iridium, or ruthenium is the optimal choice depends on the application and acceptable tradeoffs.


not all created equal. Manufacturer's may have more than one line of platinum, iridium, or whatnot plugs that vary in service life and price,


How long did the spark plugs last before you felt firing problems?

About 150hrs on both

 

[SC Maintenance]

My Nissan's spec NGK laser Iridium for 105K. Why 105 - no idea. I have run them 100K several times and they always came out looking OK. Posted the here last time I did it - general consensus was they looked good.

 

[The motor guy]

About 150hrs on both

Guess they need to be changed every 100hrs on the dot like the manufacturer asks

 

[The motor guy]

My Nissan's spec NGK laser Iridium for 105K. Why 105 - no idea. I have run them 100K several times and they always came out looking OK. Posted the here last time I did it - general consensus was they looked good.

105k is probqbly 5k outside the warranty period, that's why

 

[JavierH19]

About 150hrs on both

Where did you buy them, if they only lasted 150 hours they must have been fake or somehow defective. I know boat engines run at high rpm's for longer but that's not that abusive for iridium plugs. Saving a few bucks buying them online is never worth it on spark plugs compared to buying them at a chain parts store. I'd also never buy a returned box at the parts store since those can be swapped out and returned by a scum customer. You can tell when they've been opened for the first time. My biggest fear is those fake junk plugs separating and destroying the engine.

 

[jayjr1105]

If you buy iridium plugs from amazon or ebay there's a better than not chance they are counterfeit. Avoid for plugs. Rockauto or real auto shops only.

 

[The motor guy]

Where did you buy them, if they only lasted 150 hours they must have been fake or somehow defective. I know boat engines run at high rpm's for longer but that's not that abusive for iridium plugs. Saving a few bucks buying them online is never worth it on spark plugs compared to buying them at a chain parts store. I'd also never buy a returned box at the parts store since those can be swapped out and returned by a scum customer. You can tell when they've been opened for the first time. My biggest fear is those fake junk plugs separating and destroying the engine.

These were the factory plugs in both situations

 

[vavavroom]

About 150hrs on both

Is the resistance of the coils within spec?