Iridium worth it over Ruthenium?

[Bwalker]

I haven’t seen the term “ Double Iridium “ used, at least at Rock Auto. They do use the term “ Double Platinum” I have been using AC Delco and for the last 18 years they are what you would call “Double Iridiums. Here are pics from three different plugs the first two shots were in a 6.0 Chevy for an amazing 180,000 miles.

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The next two shots are for an AC Delco 110 that went into the engine in 2018. It is also a “ Double Iridium.

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They are going to be pulled this summer at about 290,000 mile and this new set of 165’s is doing in. This is Chevy’s newest design for Gen IV engines. Notice the “collar” at the base of the electrode. It too would be considered a “ Double Iridium.

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The "double" just means the electrode is iridium and the ground strap has an iridium disk.
If both places are not iridium the steel of the ground strap burns away opening the gap and the iridium electrode is a waste at that point.
I out Ruthineums in my vehicle. They have a center electrode of ruthenium and a disk on the ground strap of some exotic metal.

 

[Snagglefoot]

There was a time not long ago when plugs were changed at 5k, and now you're complaining at 100k....

“ Get a Champion Tune Up”

 

[D60]

The "double" just means the electrode is iridium and the ground strap has an iridium disk.
If both places are not iridium the steel of the ground strap burns away opening the gap and the iridium electrode is a waste at that point.
I out Ruthineums in my vehicle. They have a center electrode of ruthenium and a disk on the ground strap of some exotic metal.

I think this is what Denso calls "TT" or twin tip. However, their marketing says:
"

• Iridium with Rhodium Center Electrode -- DENSO uses the highest concentration of Iridium of any spark plug and outperforms in the most severe engine temperatures, resisting oxidation and voltage wear for over 100,000 miles.
• Platinum Ground Electrode -- extends the life of the plug by resisting gap erosion."

But they do have the disc or nub visible on the ground strap. So, maybe that's platinum per the wording above?

 

[Snagglefoot]

I think this is what Denso calls "TT" or twin tip. However, their marketing says:
"

• Iridium with Rhodium Center Electrode -- DENSO uses the highest concentration of Iridium of any spark plug and outperforms in the most severe engine temperatures, resisting oxidation and voltage wear for over 100,000 miles.
• Platinum Ground Electrode -- extends the life of the plug by resisting gap erosion."

But they do have the disc or nub visible on the ground strap. So, maybe that's platinum per the wording above?View attachment 327562

I’d agree with that assessment. The platinum ground electrode would just be the small piece, not the entire electrode. It would be way too expensive.

 

[zzyzzx]

How hard are the spark plug to change on this vehicle?

 

[SOUNDMAN5000]

I know my thought may not apply to this situation and I do understand and have used high end spark plugs in my modern supercharged and turbo engines but 20+ years ago with the purchase of a Harley that the plugs were super easy to get at and remove I decided to try every plug available over a period of about 2 years, as more of a test to find the best plug for the bike.

Say what you will about a Harley being old tech but riding on top of a engine with wheels and knowing the bike well the slightest change I could feel via my "Butt Dyno".unlike in a car. Platinum, Iridium, E3 etc, I settled on the best running, best butt dyno, best EZ starting plug and that plug was the basic Copper AUTOLITE $5.99 taking the WIN!

In that old bike I can change the plugs in 2 min, so long lasting 100K mile plugs was NOT the goal, best running was.
I know old school copper won't last long but I ask is copper ( least resistance ) the best way to pass electrons and get a spark be it only a few thousand miles? I wonder but I guess my point is I will always question spending crazy amounts on spark plugs.

Personally I treat plugs like my oil changes. I don't try to get hyper miles on a oil change using $$$ boutique oil. I use normal oil but simply change it often.

I once purchased used Police cars at auction and got to know the guys at the shop that maintained 150+ fleet of Police Vics, I will never forget the County garage manager telling me he once had a fleet wide issue of coil packs going out on the Crown Vic, He went from 100K to 60K plug changes and his failed coil pack issue went away.

He also said the Crown Vic was the best Police Car ever made!

As far as relating to this thread, I ask do these longest lasting 100K+ mile Precious metal plugs that last so long have a trade off to get that kinda high miles on a plug? I would be worried a plug would simply get stuck leaving in in an engine so long...
I will never un-hear what that guy told me about his coil packs going bad so 60K max is what I try and do. why not?

 

[D60]

There was a time not long ago when plugs were changed at 5k, and now you're complaining at 100k....

I pulled some factory platinums out of '08 or '09 FJ Cruiser with ~230k freedom. You knew they were factory because that was right on the cusp (again either '08 or '09 -- I've forgotten) when Toyota switched from platinum to iridium.

The gap was huge but honestly the vehicle drove fine. I'm sure some efficiency or MPG was lost but from the driver's seat you wouldn't know it (shrug)

I'm not advocating super long intervals but rather marveling at how far we've come. A single-coil distributor based system wouldn't tolerate this as well (although I've seen it on an XJ Cherokee)

 

[TomYoung]

There was a time not long ago when plugs were changed at 5k, and now you're complaining at 100k....

I guess 100 years is “not long ago.”

 

[TomYoung]

How hard are the spark plug to change on this vehicle?

The front bank is easy peasy. The rear bank requires wobble extensions, extensions of various sizes and spark plug sockets that have foam or grabby stuff. Masking tape and duct tape and a mirror on an extension wand don’t hurt, and a stable step stool helps. If your chest is not on the engine, you’re not doing it right. All that said, it is by no means impossible. It is harder than it should be.

 

[zzyzzx]

The front bank is easy peasy. The rear bank requires wobble extensions, extensions of various sizes and spark plug sockets that have foam or grabby stuff. Masking tape and duct tape and a mirror on an extension wand don’t hurt, and a stable step stool helps. If your chest is not on the engine, you’re not doing it right. All that said, it is by no means impossible. It is harder than it should be.

As the owner of a V6 Alero, I can relate. I'd also add that I expect extra difficulty removing mine since they have been in the engine since 1998 as well.

 

[Kestas]

Sometimes manufacturers do things like use a different precious metal chiefly to differentiate their product from others. I've been involved with such programs on other products. "Everybody" uses platinum. They want to be different.

 

[Kestas]

I've had double platinums where the top pads were blown off after time. I don't know how prevalent that problem is. Mine was just a singular experience.

 

[tcp71]

Rutheniums are generally thought of as the better and longer lasting plug.

• Longevity: Ruthenium generally lasts longer (up to 120k+ miles) compared to Iridium (100k+ miles).
• Heat Resistance: Ruthenium has slightly better heat resistance, making it more suitable for high-performance applications.
• Ignitability: Ruthenium's design often provides better, faster ignitability, which can lead to better fuel efficiency and smoother engine performance.
• Cost: Ruthenium is typically more expensive, though the price difference is narrowing

 

[Nukeman7]

I will be replacing the plugs in my MDX shortly. It's at about 104k miles on the factory Iridium plugs. Interestingly, NGK does not spec a ruthenium plug for me and instead only gives the laser iridium part number despite the 2016+ Pilot with the same J35 engine having a ruthenium option. My only guess as to the reason for the discrepancy is that on premium and a more aggressive timing profile the MDX has slightly higher performance, and therefore they want the better conductivity of iridium? I'm sure I'd have zero issues using the ruthenium part number allowed for the Pilot, and it looks to be just over half the price of the iridiums. All that said, I can get a set of 6 iridium plugs shipped from RA for under $100, so not a deal breaker. Thoughts?

How hard are the spark plug to change on this vehicle?

This $14 tool makes replacing the rear plugs on a Honda J35 V6 engine child's play. I've used NGK Ruthenium plugs to replace the original Laser Iridiums on a few Hondas and Nissans and have seen no difference in performance.

 

[D60]

This $14 tool makes replacing the rear plugs on a Honda J35 V6 engine child's play. I've used NGK Ruthenium plugs to replace the original Laser Iridiums on a few Hondas and Nissans and have seen no difference in performance.

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Don't buy the single when you can buy the whole assortment such as the 80601 set!!

Net Man Points deduction for not suggesting a larger set! Mo tools mo betta

 

[burbguy82]

Of course, double iridium is like, three times as good as just regular Iridium. Do the math.

 

[tbm5690]

The front bank is easy peasy. The rear bank requires wobble extensions, extensions of various sizes and spark plug sockets that have foam or grabby stuff. Masking tape and duct tape and a mirror on an extension wand don’t hurt, and a stable step stool helps. If your chest is not on the engine, you’re not doing it right. All that said, it is by no means impossible. It is harder than it should be.

Rear bank will be a cakewalk. Context: previously owned a VQ Maxima, 2GR Highlander, 3MZ RX, and a Duratec Mazda 6. All of those required intake manifold removal. This will be the first transverse V6 I've owned not requiring that. I'm a happy camper.

 

[tbm5690]

This $14 tool makes replacing the rear plugs on a Honda J35 V6 engine child's play. I've used NGK Ruthenium plugs to replace the original Laser Iridiums on a few Hondas and Nissans and have seen no difference in performance.

View attachment 328118

I already have a similar sized swivel extension, and a spark plug socket of course so hoping that will do.

 

[dogememe]

NGK Iridium IX is a cheaper option (vs Laser) and has an application for the MDX. I used these on one of my older Mazda's without issue.

IX is not a longevity plug and I wouldn’t recommend it on an application where the plugs are difficult to change.

 

[martinq]

Has anyone posted the spark plug test video from Torque Test? Seems that counterfeit plugs are everywhere:

Torque Test Channel
Mar 13, 2026
We Tested $500 in Spark Plugs, 33% were Counterfeit