Spark Plugs: Copper vs Iridium vs Platinum FF#32

[pgill]

Excellent post

Thanks for sharing

Here is a graph from Denso showing the evolution of Nickel to Platinum to Iridium spark plugs

Denso_timeline.jpg (110.98 KiB) Viewed 7491 times

[KLR142]

Definitely voodoo. We use those plugs on almost all of the 99-2009 5cyl turbo cars(except the 2.5T5/R motors and the 2.5Ts in the P1 chassis cars) without issue at our shop and have sold thousands over the years.

[precopster]

It could be one of them was faulty. Replacing them one at a time would have been a more accurate way of determining if it were the plug(s)

I don't see what all the fuss is about plugs. If the fuse on a stick of dynamite is made of rope with some sulphur impregnated or a viscose fuse the resulting bang is determined by the amount of dry gunpowder contained in the dynamite, and how tightly packed it is; not the fuse material. The analogy here is the fuel/air mixture being the gunpowder and the compression the engine provides. Once it's lit whether by Iridium, copper or platinum the bang is the same.

If we're chasing longevity that's a totally different issue

[mrbrian200]

You know, those cases where voltage arcs between a couple of the pins at the TCM connector disrupting CAN communication.. Those pins are are separated by a couple millimeters. The voltage potential to arc across that distance is way higher, by a factor of hundreds or maybe even thousands, than would normally be found on those wires.

I've always suspected these cases were ignition/spark voltage that is somehow finding it's way where it's not suppose to be to arc across inside that connector. The million dollar question is why/how. As many people use these plugs without issue I tend to lean toward a problem in the wiring loom or engine to chassis/chassis to battery grounds. Or maybe even carbon buildup or dielectric that has gotten into the plug threads on the cylinder head. If even half of the spark current ends up where it's not supposed to be, the spark might still jump at the plug gap (the cylinder fires, no misfire codes) with enough current shunting in parallel inside TCM connector to disrupt CAN communication.

Unless it's due to something relatively simple (like a bad chassis or battery ground) it'll probably take a trained electrical engineer and some reverse engineering on one of these to figure it out. Might be beyond typical ASE level training/understanding to determine exactly whats happening with certainty. Until a root cause is determined one 'fix' might work for one car but not for another...

[DeadEric]

I was always told "use OEM plugs, always. If it came copper use copper, if it came platinum use platinum. Don't use Autolite if it came NGK (or whatever the brands.)" Okay makes sense. Obviously, non stock cars may have other considerations.

Now, being one that doesn't take "just being told" as the truth, I did some rabbit hole research. There are millions of opinions but not a lot of scientific facts on spark plugs. The rabbit was deep. One thing that was repeated the most was...

Engineers design ignition systems around the components. Meaning, with OEM components the computer knows the exact dwel time for the ignition coil, what is coming out of the coil, how much resistance is between the coil and the plug, what the plug is going to do with what it gets and what happens to the voltage after it jumps the gap. With newer cars and more monitoring of the ignition system, subtle changes in materials and manufacturing practices can be noticed and cause issues.

I took that as good advice for the average car owner, use OEM. May not be "the best" thing out there but it is what your car knows and shouldn't cause any issues.

Then I saw something about heat dissipation from one material (copper or platinum) to the next and copper does it better but platinum lasts longer and oh yeah, some company makes plasma plugs and they are the only "real different spark plug" because with plasma there isn't the flame front propagation issue and blah blah blah. Some manufacturers require you to index your spark plugs. 4 prong plugs are better than 2, but they are better than 1. A spark plug is a spark plug, they all burn gas...

Sorry I took you down my rabbit hole, it was much worse than that last paragraph. I do appreciate the post and the time that went into it.

[pgill]

DeadEric,

Some times its better to take the Blue Pill

But if we must then we will take the Red Pill and find out just how far down the rabbit hole really goes.

Just my $.02

When selecting new spark-plugs I consider the following

1. Use the same electrode material as stock unless you have a good reason for changing it

2. Use the same heat range as stock unless you have a good reason to change it

3. Use the OEM spark-plug manufacturer as the preferred choice

Note: the fuel system on my 3.2 is made by Denso so for me Denso is the best choice

4. Consider upgrading to New technology if Volvo switched in later model years (same or similar engine type)


Let me give an example of item #4


Denso SK20HR11 - this is the original spark-plug that came on my S80 3.2 and it is a very good choice if you hate to change plugs

Denso (5344) IKH20 Iridium Power Spark Plug - a finer wire version of the stock plugs, I've run these in my 3.2 for over 50,000 milles

Denso (4704) IKH20TT Iridium TT - this is a fine wire twin tip version of the spark-plug (Volvo switched to TT plugs in later years)

Take a look at this thread for more information

viewtopic.php?f=10&t=88362


My research on the TT plugs found that the big advantage of this type of plug is that initial flame kernel is not surrounded by a lot of metal which is very helpful for preventing flame quenching at idle and part throttle. I did switch to TT plugs in my Audi 2.0T and the part throttle response is significantly better and the idle is a lot smoother. I also installed TT plugs in my neighbors Toyota to get rid of a P0420 code. Note: the TT plugs did not produce any more power at WOT (wide open throttle)

From my perspective if the Volvo engineers are willing to incorporate a new technology in their design then the new component must have a compelling advantage. And that is exactly what they did in later years.

Take care

Paul

[ThommyKent]

I`ve had a new spark plug manufactured wrong and was defective. If it`s running fine just leave it alone with what`s in there

[Sommerfeldt]

It's a little strange to see "keep it like it was made" in a Performance forum, where just about everything revolves around what we can do to make cars better, faster, stronger, etc.

If there's new technology that can improve the life cycle, driveability, joy and fun of a car, why not use it? Or should we all go back to carburators and lead-lined gas? How about gum rubber brake lines - drum brakes, for that matter?

My aging 850 runs Iridium. It likes them very much, when they're gapped properly (as with all kinds of plugs). I'm also not going back to OEM shocks - I like my Konis. I'm also getting braided brake lines for my aging OEM ones - you can't talk me out of it. As to what the car "knows"? Someone mentioned voodoo up here - the car knows what the car is told. It talks to sensors and feedback, not brands or materials. It looks at air and fuel, and whether it's burning right, not what ignites it.

Oh, and I'm not writing this on a Tiki 100. It's a laptop I upgraded myself, with parts the processor didn't know would exist when it was made and installed... so, yeah.

- S

[pgill]

S,

I'm not sure if I understand your question/comment

I recommended (for the 3.2 Liter)

Denso SK20HR11 - this is the stock plug and it is an excellent choice for longevity

Denso (5344) IKH20 Iridium Power - a good choice for smoother idle and better part throttle application

Denso (4704) IKH20TT Iridium TT - The best choice for smooth running and part throttle application

If Volvo had specified a copper plug stock on my 3.2 then I believe that any of these would provide a significant power improvement but because the stock plug was an iridium plug the performance gain was minimal.

I will say that my 2010 S80 3.2 did respond very well to new spark plugs, new air filter, new ATF, synthetic motor oil, MAF cleaning.

These items did restore a significant amount of power.

But it is unlikely that my 3.2 makes more power today as compared to what it was making at 23,000 miles.

Having said that if the Stock plugs for your Engine are Copper or Platinum plugs then the Iridium plugs are worth a try.

Which Iridium plugs are you using on your 850? how long have you been using them? What is your planned change interval?

Have you considered using the TT iridium plugs?

I made the switch for my Audi 2.0T and I am very happy with them.

Thanks

Paul

[mrbrian200]

OE plugs may not be the best possible 'configuration' that can be achieved, but reconfiguring properly goes beyond simply throwing a different plug under there. With something as 'big' as the spark plugs you need to take the car to a tuner to have the ECU software/maps customized - else at best you simply won't likely gain the full potential advantage of using those alternate plugs, or at worst you risk engine and/or catalyst damage.