Clarification on Upgrading Spark Plugs

[Gebo]

I was "told" or "read" or "heard" that you should only stay with the type of spark plugs that came in your vehicle. If my vehicle came with platinum plugs I should stay with platinum plugs. If standard copper core I should stay with standard copper core. I should not move up to iridium if my vehicle did not come with iridium plugs to begin with. I know when I look up NGK plugs for my cars I am given all these different plug choices which gives me the impression I can use either the V Power, Platinum, Iridium, etc.

My understanding is the electronics set up is different for different types of spark plugs. And that my car will work better if I don't switch from Platinum to Iridium as the ignition system was set up for Platinum plugs.

Is what I have been believing the truth or a lie?

 

[SteveSRT8]

Completely true but wildly platform dependent. I know Mopar owners who have changed their 5.7 from coppers to NGK hybrids and had excellent results. But the Net is rife with tales of terror.

Some mfgrs have extremely sophisticated ignitions that depend on certain plugs to function properly. Others are not as fussy.

 

[Snagglefoot]

All grandpas should stay with the originals. All others should run Iridiums.

 

[FordBroncoVWJeta]

I've run $1 coppers and the expensive double iridium. Can't tell a difference versus OEM $25 Volkswagen spark plugs.

"Platinum and Iridium plugs perform at a lower level than copper spark plugs, because they are less conductive and they tend to overheat. ... However, the overall longevity of these two types of metal is better than copper plugs. In reality, copper has the best performance of all three and the worst longevity."- Google

 

[demarpaint]

MY 3.7L Liberty calls for copper plugs. I swapped them for Iridium plugs at about 30K miles ago, so far so good. Although they're very easy to change I wanted a longer lasting better plug. I guess it is vehicle dependent as SteveSRT8 stated. I haven't had a problem yet upgrading plugs, as long as they are the right size and heat range for the vehicle. Having said that I will do my homework before I upgrade the plugs in my 2016 Wrangler, they're a PITA to change.

 

[Astro14]

Originally Posted by FordBroncoVWJeta
I've run $1 coppers and the expensive double iridium. Can't tell a difference versus OEM $25 Volkswagen spark plugs.

"Platinum and Iridium plugs perform at a lower level than copper spark plugs, because they are less conductive and they tend to overheat. ... However, the overall longevity of these two types of metal is better than copper plugs. In reality, copper has the best performance of all three and the worst longevity."- Google


Well, as Abraham Lincoln said, "You can't believe everything you read on the internet"

Look, ALL sparkplugs have copper cores for both electrical and heat conductivity. "Copper" plugs have copper cores, but not copper electrodes. The electrodes are nickel alloy. The more exotic electrodes, like platinum or iridium are simply a few mm of that material, chosen because the higher melting points of those materials allows for a sharper electrode (which yields better flame) and longer life.

The difference in conductivity of nickel, platinum, or iridium in the few mm of electrodes beyond the copper core is meaningless.

In some cars, the use of iridium plugs is important because the gap is different, and the life is longer. I would stick with what the car came with. No one makes iridium plugs for a '32 Packard for example, and those "copper" plugs have a nickel alloy electrode, which is enough for the 6 volt ignition system and 6.5:1 compression. Iridium electrodes in that car would be useless.

When I hear people like Scotty Kilmer (loud, but frequently wrong) rant about how copper is soft and wears out quickly, I wonder if he's ever actually LOOKED at the plugs he is installing. "Copper" plugs have silver electrodes. Nickel alloy. No sparkplugs have copper electrodes.

Sorry, Google, wrong again...

 

[Gebo]

So nobody knows? We are just all doing whatever feels right? LOL

 

[Snagglefoot]

Here's the problem. In spite of plugs being hard to install in some vehicles, many of use get great satisfaction in changing them, much as many of us like changing the oil. The truth is Iridium plugs now routinely last 100,000 miles. I changed at set at 180,000 miles and they still functioned fine at the time.

As far as ignitions go, I don't believe at all that some special ignitions need any plug other than Iridiums. It's internet garbage.

Using copper plugs? Might as well get out the buggy whip.
Unless you enjoy changing plugs so much that you're doing it 3 to 6 times more often.

Iridium Guy

 

[BMWTurboDzl]

Stick with OEM specification because the engine is tuned for it. The only benefit of using a "premium" plug is additional life, but does it really matter that you can get 100k miles out of Iridium vs say 60k on Platinum? Naw...not really.

Now if you're increasing power with a tune/forced induction then you'll need to find a plug with a different specification (ex. colder) which could either be platinum or iridium.

 

[Sam_Julier]

In our Volvo 240s I have run both the standard, least expensive, NGK Copper/Nickel 7131 and the slightly more expensive NGK Copper/Platinum "G-Power" plugs. I can't tell the difference except that the G-Power plug looks less worn at 20,000 miles. I settled on the G-Power and change them at 20K along with the rotor and cap.

Sam

 

[ragtoplvr]

I have never had a car run worse on platinum plugs. I have seen a conventional (copper core encased in nickel alloy) plugs run differently. In my limited personal experience champion or NGK U electrode plugs do better in classic Chrysler products, and AC Delco tend to do better in classic GM products. However replacing a conventional copper core nickel encased plug with platinum or iridium is the same. I am a fan of the BOSCH platinum 4+ platinum plug in my BMW motorcycle as it really outperform the standard 2 electrode copper core nickel NGK plug. However that application has the spark located horizontal in the chamber and I do not know how that would work replacing a vertical spark conventional plug. I know many owners like replacing the NGK with an Autolite conventional plug but for me it only lasted for about 1000 miles while the bosch have lasted for 50K miles. It would be an interesting experiment to see how 4+ plugs react in different engines.. The compressed mixture in most cars is swirling and tumbling in a specific pattern, moving the location of the spark is unpredictable. But for me, I will just use the original plug design in platnum as long as there is no problem to solve like short life or bad running.

Rod

 

[Gebo]

I'm not under the impression that changing the type of plug will affect performance. A spark is a spark, right ?

I'm wondering if it will do long term damage to the vehicle's electronics if you replace a common plug with an iridium?

 

[Donald]

Some cars with a "waste spark" ignition (Jeep 4.0 engine) use one coil for every pair of cylinders and both cylinders get a spark during the intake and exhaust. I believe that from the factory they had a matched set of plugs per coil (a left and right plug) but you could not buy those and so they said it was best to use copper or double platinum. This is what I have been told. Unsure if its really true other than the vehicle does have a waste spark ignition.

 

[Snagglefoot]

Originally Posted by Donald
Some cars with a "waste spark" ignition (Jeep 4.0 engine) use one coil for every pair of cylinders and both cylinders get a spark during the intake and exhaust. I believe that from the factory they had a matched set of plugs per coil (a left and right plug) but you could not buy those and so they said it was best to use copper or double platinum. This is what I have been told. Unsure if its really true other than the vehicle does have a waste spark ignition.


The replacement plugs for the waste spark ignition on my two Taurus's are normal platinums. I was too cheap to by Iridiums. And yes, they don't make the original matched set any more. I didn't buy Iridiums because the Platinums will probably outlast the cars.

 

[BMWTurboDzl]

Originally Posted by Gebo
I'm not under the impression that changing the type of plug will affect performance. A spark is a spark, right ?

I'm wondering if it will do long term damage to the vehicle's electronics if you replace a common plug with an iridium?


No, spark plugs have a heat range, as long at the iridium has for example the same heat range as the OE plug you should be fine. I'm assuming the iridium is physically compatible with the cylinder head in terms of depth and thread pitch.

 

[doitmyself]

Originally Posted by Snagglefoot
Originally Posted by Donald
Some cars with a "waste spark" ignition (Jeep 4.0 engine) use one coil for every pair of cylinders and both cylinders get a spark during the intake and exhaust. I believe that from the factory they had a matched set of plugs per coil (a left and right plug) but you could not buy those and so they said it was best to use copper or double platinum. This is what I have been told. Unsure if its really true other than the vehicle does have a waste spark ignition.

The replacement plugs for the waste spark ignition on my two Taurus's are normal platinums. I was too cheap to by Iridiums. And yes, they don't make the original matched set any more. I didn't buy Iridiums because the Platinums will probably outlast the cars.

The Ford Escorts also came from the factory with 2 different plugs - 2 had platinum center tips, 2 had platinum grounds. The Motorcraft replacements were one plug with double platinum.

@ GEBO - I understand your concerns. The internet implies that a vehicle's ignition system is "tuned" to the type of plug. Chryslers that come OEM with standard "copper core"/nickel electrode plugs probably elicit the most doubt. For what it's worth, numerous guys on the Jeep forum I frequent have used plugs other than the OEM standard conventional plugs without reported problems. Yet, others insist that the copper core/nickel electrode is all you should use. Go figure. Some say that the platinum or iridium plugs need more energy to fire, while others state the opposite.

Edit: I just emailed NGK to see if they have any facts beyond CYA language.

 

[Imp4]

Assuming we are comparing components in good working condition, no spark plug upgrade from OEM is going to noticeably change your engine's output performance.

If it were possible, it would be because of significant unburned air/fuel mixture within the combustion chamber.

If you had that condition, you would have much bigger problems on your hands other than which spark plug is appropriate for your application.

Exotic electrode spark plugs result in longer service life for the user, not any sort of performance gain.

The unfortunate reality is that because spark plugs are easy to change out, companies market claims of huge performance increases and shade tree mechanics buy the nonsense.

Of course there are exceptions to this assessment, but for the vast majority of consumers, what I have stated earlier is true.

 

[Gebo]

I'm not communicating properly. I'm talking about the affect on the electronics prior to the spark plug. I'm not asking about performance or anything mechanical within the engine.

I'm talking about any component before the actual spark plug itself.


Even as far as affecting the wires, could and even computer long term.

 

[BMWTurboDzl]

Originally Posted by Gebo
I'm not communicating properly. I'm talking about the affect on the electronics prior to the spark plug. I'm not asking about performance or anything mechanical within the engine.

I'm talking about any component before the actual spark plug itself.


Even as far as affecting the wires, could and even computer long term.


NO. Plugs don't generate current they only receive it.

 

[CT8]

It is just easier to use what was OEM. I had a 92 Toyota truck with a 3.0 bought new when I did the first spark plug change 1 head had NGK spark plugs and the other head had had Denso spark plugs. Both brands were the same types.