Platinum, Iridium, Ruthenium, oh my!

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I haven't used ruthenium plugs yet. While I do think OEM is the way to go(especially on FWD transverse V6s and some RWD engines), if the car came with standard plugs, the choice is yours.

I should have used these or a Ir/Pt plug in a friend's Explorer.
 
I pulled a factory platinum plug out of the Impala the other day, and it looked surprisingly good for 185k miles. I measured the gap at .055", factory gap is .040". I'm leaving them in. It runs great, has plenty of power, and gets great mileage for what it is. The wires and coils are original, as well.
 
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I too would dispose of the platinums. They are redundant considering the other options. I default to iridiums, they are a great value striking balance between price and durability. Rutheniums seem an attractive option, but I still would pull my plugs every 100,000 miles to be sure they haven't seized and to check their running condition. I don't have any road vehicles that call for coppers, but if I did, I would surely upgrade copper plugs to iridiums at the next service.
 
I have replaced all my OEM NGK plugs with Denso TT platinum. They work fine but my engines are all 4 cylinders, a 30 minute job to replace.

If I had a FWD V6 of course I'd replace the plugs with the next iteration which will have electrodes made from unobtanium.
 
Originally Posted by DGXR
I too would dispose of the platinums. They are redundant considering the other options. I default to iridiums, they are a great value striking balance between price and durability. Rutheniums seem an attractive option, but I still would pull my plugs every 100,000 miles to be sure they haven't seized and to check their running condition. I don't have any road vehicles that call for coppers, but if I did, I would surely upgrade copper plugs to iridiums at the next service.
Okay - here is another reply that addresses the question I was asking. Do we really need Platinum plugs when Iridium is clearly better? And how do we all feel about this, considering that Platinum has been the OEM choice with some higher end automakers for the last 20 years, and many more for the last ten?

My original thoughts when starting this tread were that we need copper / nickel plugs for less demanding OPE, generally meaning the low compression 2-cycle stuff. Iridium seems to be the leading edge for most high compression engines, with little cost premium over Platinum. Ruthenium is the latest and greatest, what we in the technology sector call "bleeding edge," may or may not replace Iridium.

So why do we still need the Platinum option? Please consider that most of you now have such plugs in your car.
 
Originally Posted by Astro_Guy


So why do we still need the Platinum option? Please consider that most of you now have such plugs in your car.

Many people see Pt as the "premium" plug, no doubt due to how Bosch in the 1990s marketed them, and Ford/GM promising 100K "tune-ups" thanks to Pt plugs.

When Toyota introduced platinum plugs as standard in the Supra/Cressida in the 1980s, they touted longer life - 60K replacement. Toyota introduced iridium plugs in the 2000s.
 
Most vehicles with factory Iridium plugs will be in the wrecking yard with the original plugs still in the heads.
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Depending on how difficult they are to get to.....if they're like the 5.4 Ford Triton or something like that.....I'd get the longest lasting ones and hope to never touch them again.....for my chainsaw - just any base NGK will go in. If stock with an exotic metal plug - the same or 'better'.
 
Originally Posted by tundraotto
Depending on how difficult they are to get to.....if they're like the 5.4 Ford Triton or something like that.....I'd get the longest lasting ones and hope to never touch them again.....for my chainsaw - just any base NGK will go in. If stock with an exotic metal plug - the same or 'better'.


I'm with you. Not all of the common "pain in the rear" spark plugs are really that bad (Ford Duratec V6 comes to mind, they're easy), but there are some that the less you have to do them, the better. Nothing wrong with advancement in tech!
 
I thought the rule of thumb was that Iridium's last to about 100k miles.

So how long are the Ruthenium supposed to last?
 
As i look it up , the melting point of iridium is 4435f. Ruthenium has a melting point of 4233f.

So i don't see the advantage over iridium.

Now the cost is different. It seems ruthenium is far less expensive than iridium, so better profit margin.
 
Originally Posted by Astro_Guy
Originally Posted by DGXR
I too would dispose of the platinums. They are redundant considering the other options. I default to iridiums, they are a great value striking balance between price and durability. Rutheniums seem an attractive option, but I still would pull my plugs every 100,000 miles to be sure they haven't seized and to check their running condition. I don't have any road vehicles that call for coppers, but if I did, I would surely upgrade copper plugs to iridiums at the next service.
Okay - here is another reply that addresses the question I was asking. Do we really need Platinum plugs when Iridium is clearly better? And how do we all feel about this, considering that Platinum has been the OEM choice with some higher end automakers for the last 20 years, and many more for the last ten?

My original thoughts when starting this tread were that we need copper / nickel plugs for less demanding OPE, generally meaning the low compression 2-cycle stuff. Iridium seems to be the leading edge for most high compression engines, with little cost premium over Platinum. Ruthenium is the latest and greatest, what we in the technology sector call "bleeding edge," may or may not replace Iridium.

So why do we still need the Platinum option? Please consider that most of you now have such plugs in your car.

I suspect platinum has been the plug of choice for manufacturers because bean counters influence a lot of the decisions. Bottom line: meet the required performance/durability spec for the lowest possible cost. So we get platinum plugs. Even a savings of $5 per vehicle will add up quickly when you're cranking out hundreds of thousands of vehicles. For example, my 2006 Tacoma 4-cylinder has a coolant bypass pipe made of plastic -- not a good material choice for a part that experiences extreme temperature fluctuations on a daily basis. It survived the warranty period so it met the requirement and Toyota is off the hook. Toyota probably saved a few dollars each over the superior coolant bypass pipe made of metal. But this is one of my very few gripes about this otherwise very solid pickup truck.
 
The average new car is kept six years. Platinums are probably fine for that and Iridiums make it probable that the average new car buyer will never change the plugs before they get rid of the car. People who lease don't care what spark plugs come in a car and typically won't be getting the spark plugs changed before returning the car. Also, manufacturers don't care about the second owner.

For me, not much of a reason to use Platinums if Iridiums are available. If Rutheniums turn out well, and the manufacturers install them in new vehicles, it's possible for the vast majority of car owners, spark plugs will no longer be a maintenance item.
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For me i just use oem iridium tt or ruthenium for new car and for older model just find the comparable model. Both has been proven long lasting, produce good power and very reliable for long run
 
All I care about in plug is ignition reliability/stability/repeat-ability and longevity.
From my 17 years era of VW experience - Plats never performed as well as Silbers or Copper plugs, and I tried a few makes and models of Plat plugs.
Nowadays, I go straight to Iridium plugs but will try Ruth next time I change plugs in Forte, it seems reports are Ruth give better ignite-ability than Ir and last longer.
 
I have a platinum-iridium out of my old Lincoln LS kicking around on my desk that was changed at ~125K miles. It gaps at .050, and the spec gap is .044. I'd have put it back in had it not been for the fact that I had at least one bad coil, wasn't sure which it was so on advice went ahead and did all 8(it wasn't much more work than changing the front most ones on each side, which would have been the best guess of the bad ones), and changing the plugs added about 5 minutes onto each coil swap. I did notice a difference in power, idle smoothness, and overall driveability when I put it back together, but I attribute that more to the intermittently failing coil being replaced than the plugs themselves.

I've spent some time looking at this particular plug under a microscope, and it's also interesting to me to see how it has worn. The ground strap is badly eroded and pitted across a lot of the surface, but there's a thin strip-presumably a platinum wire-that looks virtually brand new. Similarly, the electrode tip is a bit less pointy/more rounded off than a new plug, which is where I suspect most of the gap loss is from, but it overall looks pretty good.

I may pre-emptively do the MKZ when I hit 100K, but I'll weigh my options on it and see how difficult the job is(I know a lot of transverse Vs can be difficult on the back side) and may defer doing it until I see a good reason to. If I have to do it, I'll do iridiums.

The old British stuff get good old fashioned plain copper NGK BP6ESs. I've never seen any benefit from Platinum, while a mis-adjusted carb can foul them up easily, and they're easy to change. I know people who swear by Champions, which were the OEM supplier, but I've been less than happy with the quality on recent Champions. I have probably a dozen sets of the NGKs put back as I hear intermittent rumors about them being discontinued, they can be hard to find in stock, and they can make a good ~$8 filler at parts houses that I know carry them if I need to push my bill up a few bucks for a special or whatever. As a side note, if you look up year/make/model on my stuff, most of the parts house computers will return the resistor version of the plug(BPR6ES) which I don't like since I always run resistor wires. I've found myself with a blank stare at stores before when I ask for the plug by P/N instead of supplying year/make/model.
 
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