Why call standard spark plugs “copper plugs”?

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I get that it’s common even though incorrect. But even supposed auto professionals call them that and double down by claiming that copper electrodes don’t last as long. Nobody would make a copper electrode. It would erode in no time. It’s a copper core for better heat transfer.

But I see stuff like this:

Quote:
http://www.mercedesmedic.com/best-spark-plugs-mercedes-benz/
Copper is an excellent conductor of electricity and that is why they were used and still are used on spark plugs. Platinum performs worse when it comes to conductivity. While Iridium is a better conductor, it is not quite as good as copper material. They are inexpensive to manufacture but their main disadvantage is that they don’t last as long. They work great when new but after a few several thousand miles can decrease in performance.


This one is really bad. There’s no worries about copper melting since it’s only in the core. But they portray copper as being the electrode material.

Quote:
https://www.familyhandyman.com/diy-advice/copper-spark-plugs-debunking-the-myth/
The myth ignores the fact that an ignition spark always jumps from (and toward) the sharpest parts of the center and side electrodes. Sure, a copper spark plug has sharp electrodes right out of the box. But copper can’t maintain sharp edges very long. The heat of the spark itself and high combustion temperatures quickly wear down the edges of both the center and side electrodes. That’s because copper has the lowest melting point of all the currently available spark plug materials (copper melts at 1,983 degrees F, yttrium at 2,779 degrees, platinum at 3,222 degrees and iridium at 4,229 degrees). Copper plugs actually experience rapid edge wear and increased spark plug gap in as little as 10,000 miles. And that results in a far less powerful (and less effective) spark that can misfire, lower your gas mileage and damage ignition wires and the coil.
 
It’s the internet.

Standard plugs have some sort of nickel alloy for the electrode. Platinum and iridium are much harder allowing for a smaller diameter electrode, lowering the voltage required to jump the gap, making for a hotter longer duration spark, which allows reliable ignition of learner mixtures. Platinum and iridium also last much longer than the nickel alloy used in standard spark plugs.

All three types of plug use a copper core conductor.
 
Originally Posted By: SilverFusion2010
It’s the internet.

Standard plugs have some sort of nickel alloy for the electrode. Platinum and iridium are much harder allowing for a smaller diameter electrode, lowering the voltage required to jump the gap, making for a hotter longer duration spark, which allows reliable ignition of learner mixtures. Platinum and iridium also last much longer than the nickel alloy used in standard spark plugs.

All three types of plug use a copper core conductor.


I don't think it's the internet. It's been around way longer than that.

AC Delco spark plugs were always branded as Copper Plus. Growing up in Flint, there were a ton of GM assembly plants, as well as the AC Delco spark plug manufacturing complex. Billboards always shouted the advantage of "Copper Plus".

Champion also advertised the advantage of "Copper Plus".

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That's easy. Because when copper-core plugs first appeared, they were called that to distinguish them from conventional no-copper plugs, and nobody has popularized a new name for them.
 
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There was a time when spark plugs didn't have a copper core, when when they did, they called them Copper to set them apart from the standard plugs....now copper is standard and we have other types.

Oh, someone got there while I was typing...
 
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Originally Posted By: SilverFusion2010
Standard plugs have some sort of nickel alloy for the electrode. Platinum and iridium also last much longer than the nickel alloy used in standard spark plugs. All three types of plug use a copper core conductor.


Truth ^^^^


Originally Posted By: SilverFusion2010
It’s the internet.


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Bosch used to make a silver core plug. Better conductor of both heat and spark. I used them in both the BMWs and an XJ6. I put 90k on a set, Swapped 'em for platinums, yanked those at 10K because they didn't play well with the ignition. Ran at least 20K more
 
Autolite coppers were always the go-to back in my Mustang days... especially when spraying the daylights out of the stock shortblock. The plugs were essentially sacrificial anodes, and made it easy to creep up on the edge of ragged vs. new crankcase ventilation
smile.gif
Plus, at around $1.50 at the time, a new set every trip to the track cost less than the price of pump gas to get there...
 
I remember those commercials. They just said "Copper Plus!" over and over again. There was no explanation of how they were any different or better than other plugs.
 
Originally Posted By: andyd
Bosch used to make a silver core plug. Better conductor of both heat and spark. I used them in both the BMWs and an XJ6. I put 90k on a set, Swapped 'em for platinums, yanked those at 10K because they didn't play well with the ignition. Ran at least 20K more

Any improvement is slight though. If there's anything it's barely any better.

I'm an electrical engineer, so I've at least studied conductivity. I do understand that silver is the most thermally and electrically conductive metal, but the difference is so little that nobody would really consider making a silver wire outside of some esoteric application. It makes more sense just to use a little bit more copper. There are people who insist that silver-core audio cables sound better. Sure.

However, I don't necessarily know if the electrical conductivity of the core matters that much. There's really no "resistance" to the gap. On top of that, most modern spark plugs include a resistor (to reduce electrical interference) that's magnitudes more resistance than all of of the metals. The big thing is the sparking across the gap - either sharp edges or using a precious metal that gets hot and self-cleans.
 
Originally Posted By: mk378
I remember those commercials. They just said "Copper Plus!" over and over again. There was no explanation of how they were any different or better than other plugs.

They were copper core at a time when another metal (steel?) was more common for the core.

I'm pretty back then the electrode material was still a nickel alloy. Even with platinum/iridium plugs the platinum/iridium is still fused to a nickel alloy electrode.
 
Originally Posted By: SubieRubyRoo
Autolite coppers were always the go-to back in my Mustang days... especially when spraying the daylights out of the stock shortblock. The plugs were essentially sacrificial anodes, and made it easy to creep up on the edge of ragged vs. new crankcase ventilation
smile.gif
Plus, at around $1.50 at the time, a new set every trip to the track cost less than the price of pump gas to get there...


Me too!!
 
A neighbor's 2001 V6 Camaro which was going to be sold (cheap) was at 100K miles.

I didn't want to spend $ on "precious metal plugs" so I bought the cheapest "copper cores".

The improvement was amazing! 'So what' if you have to go back to 20K plug changes?
 
Originally Posted By: Kira
A neighbor's 2001 V6 Camaro which was going to be sold (cheap) was at 100K miles.

I didn't want to spend $ on "precious metal plugs" so I bought the cheapest "copper cores".

The improvement was amazing! 'So what' if you have to go back to 20K plug changes?

At least until the edges wear down. Denso does have their U-Groove and NGK the V-power to increase the number of edges. But they're not overpriced.
 
Sometimes referring to electrode material, other times referring to core material in the absence of a cool sounding elemental electrode tip. Next coolest sounding metal? Copper (in the core). Would you rather have a copper plug or a chintzy ol' nickel plug? I'd say the manufacturers are to blame for this.
 
Originally Posted By: PeterPolyol
Sometimes referring to electrode material, other times referring to core material in the absence of a cool sounding elemental electrode tip. Next coolest sounding metal? Copper (in the core). Would you rather have a copper plug or a chintzy ol' nickel plug? I'd say the manufacturers are to blame for this.

I was thinking the way that motor oil has gone for marketing purposes. I think "conventional" says it pretty well. Even if there are advances (like Group II/III in common motor oils) that's still considered the base model.

But it's just really odd how many so-called auto experts claim that "copper erodes faster" when the copper isn't exposed to the combustion chamber.
 
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