NGK 94567 Ruthenium HX ???

wjburken said:

What do they have for a gap? I see most of the plugs on RA, for the 6.2 at least, are pre-gapped to .040 while some of the NGK’s are gapped to .044. I don’t see a gap on the link from the OP.

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.040 from the research I've done.

iamdub said:

At ~100K miles, I'm fine with the lifespan of iridium or even platinum. But if these maintain comparable or better performance than the iridiums throughout that lifespan, then I'd get 'em. Even if they're a couple bucks more per plug, you'd recover from and forget about it long before they're due to be replaced again.

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I will most likely get these and give them a shot when I'm ready to do mine... what's the worst that could happen... lol

I was hoping to find a better deal somewhere else but so far RA seems to be the cheapest... maybe there will be some kind of rebate or sale or something before it's time for me to order them.

kbuskill said:

I will most likely get these and give them a shot when I'm ready to do mine... what's the worst that could happen... lol

I was hoping to find a better deal somewhere else but so far RA seems to be the cheapest... maybe there will be some kind of rebate or sale or something before it's time for me to order them.

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When I first heard of it, the name "ruthenium" and referring to spark plugs made me think it was a joke like the age-old "unobtainium" element.

Referring to the laminated Periodic Table of Elements I keep in my pajamas pocket... Nah, I just Googled it:

https://www.lenntech.com/periodic/elements/ru.htm

Compared to Iridium:

https://www.lenntech.com/periodic/elements/ir.htm

According to the info in those links, they're in the same group of elements and their key qualities are fairly similar other than their densities- ruthenium is almost half as dense. This prompted me to look up their hardness, which brought me to azom.com.

Iridium: https://www.azom.com/article.aspx?ArticleID=9092

Ruthenium: https://www.azom.com/article.aspx?ArticleID=9275

According to those, ruthenium is less hard than iridium on various scales and it's tensile strength is a massive 236,300 psi LOWER than iridium. I don't see tensile strength being much of a concern in this application, anyway.

This tells me the ruthenium is a softer metal than iridium which, at first thought, leads me to believe it'd wear down sooner than iridium. NGK's info says and shows the opposite- that it wears slower than iridium. Maybe iridium is actually TOO hard and more brittle than ruthenium and, in this application, wears slightly faster because it chips off more easily where ruthenium is more compliant to the sparks pecking at it?

Physical properties aside, I noticed the cost of the ruthenium plug (in our application) was over $3 higher than the iridium counterpart. So, I looked up the cost of the metals themselves and expected the ruthenium, especially with it being more rare, to be considerably higher. According to a generic Google search, the current cost of iridium is $520 per ounce and ruthenium is a fraction of that at $36 per ounce. This leads me to believe it's primarily a profit-growing change with it being a cheaper metal sold at the same or higher cost. Hell, they could sell the rutheniums for less than the iridiums to better kick off the change and still come out way ahead. But, underpricing a supposedly superior plug could raise doubt as it defies our programming of "premium price = premium product".

I'd love to see unbiased, third party scientific data comparing the two. But, as of now, it looks to be too new a product with no real world consumer experience and data to reference so any of us buying them now are guinea pigs. If the performance (as in durability and spark production, not power gains) actually IS better with the rutheniums, then maybe the extra few bucks is worth it. If you're not willing to spend the dough, then you could always stick to the tried-and-true iridiums that have been proven countless times to perform well beyond their recommended replacement interval.

Thanks for doing the leg work/research... I have Iridium plugs in it now... In all actuality they probably don't need to be changed out yet but I was looking for plugs when I saw these and thought, Hhhmmm, I wonder if they are any good.

I don't geek out often on trivial subjects, but my misguided OCD pulled me down that rabbit hole.

iamdub said:

I don't geek out often on trivial subjects, but my misguided OCD pulled me down that rabbit hole.

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Then my plan worked...

kbuskill said:

Then my plan worked...

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Well played. Though, it's two-fold since it won't be a question for me when I go to replace mine. Stock iridiums will be perfectly fine for me and the longevity isn't even a concern because of how little I drive mine.

Thought I would resurrect my old thread here VS starting a new one...

So NGK has two versions of this plug.

They have a DFE plug, which is on the left in this pic, which they recommend for naturally aspirated engines.

And they have a PSPE plug, which is on the right in this pic, which they recommend for boosted applications.



My questions are...

What do you suppose would happen if you ran the PSPE version in a N/A engine?

Their website says...

DFE (double fine electrode) maximizes ignitability, while reducing emissions for low-heat engines. This NGK-patented design is recommended for non-turbo applications.

PSPE® (projected square platinum electrode) provides the best ignitability and service life for high-heat engines. This NGK-patented design is recommended for turbo and supercharged engines.

So do you think it would give any drivability issues or idling issues or cold starting issues?

To me the plug on the right looks like it would create a better flame kernel because the tip of the plug is not shrouded.

Here is a better pic...


Kind of like the old racers trick of side gapping plugs.

I sent NGK a message to see what they can tell me but figured I would ask here as well.

Anyway... what say you all?

IMO, if the "boosted" plug has the same heat range as the NA, then I'd bet it'd make no discernible difference. Aside from that, I'd still stick with iridium for the cost and established longevity. But, I welcome real-world proof of superiority of the rutheniums.

iamdub said:

IMO, if the "boosted" plug has the same heat range as the NA, then I'd bet it'd make no discernible difference. Aside from that, I'd still stick with iridium for the cost and established longevity. But, I welcome real-world proof of superiority of the rutheniums.

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Got a response back from NGK.

They do NOT make a Ruthenium PSPE style plug for an LS engine. Not even for the ZR-1 Corvette.

So if I try these, and I probably will, it will be the DFE style I guess.