Spark Plugs! What's normal wear?

[CharBaby]

Originally Posted By: hypervish
Here's a picture of my plugs at 160k miles, sorry for the horrible picture quality...And, my paint is in much better condition now! LOL

Thank you hypervish!
Yes, this is what my plugs look like at 93K miles.

 

[grantsburg]

Originally Posted By: SHOZ
I changed the plugs on my son's '09 Chevy Malibu 4 cyl last spring. At 100k they looked as good as the new plugs I put in. I couldn't believe it.


My winter beater here in MN is a 1995 Dodge Avenger. It has 163,000 miles on it and is still using the original plugs. It averages 23 mpg and never fails to start while sitting outside in the sometimes brutal cold we experience here.

So I have no trouble believing that your 100k plugs looked as good as new. I think changing spark plugs is a thing of the past. Most people will gid rid of their car before the plugs need replacing.

 

[BurrWinder]

Originally Posted By: grantsburg
Originally Posted By: SHOZ
I changed the plugs on my son's '09 Chevy Malibu 4 cyl last spring. At 100k they looked as good as the new plugs I put in. I couldn't believe it.


My winter beater here in MN is a 1995 Dodge Avenger. It has 163,000 miles on it and is still using the original plugs. It averages 23 mpg and never fails to start while sitting outside in the sometimes brutal cold we experience here.


So I have no trouble believing that your 100k plugs looked as good as new. I think changing spark plugs is a thing of the past. Most people will gid rid of their car before the plugs need replacing.



Yes, the "newer stuff" with precious metal plugs and DIS or COP (Coil on plug/near plug) will still "run" with stock plugs to well after 100k, as the whole idea is to let them live as long as possible - BUT cylinder efficientcy, stress on the ignition system, engine management richening to compensate MEANS they still need to be replaced at like 100K or you are just missing the point. Yes, it's not like "cap,rotor wires or god forbid, points days, but the [censored] still doesn't last forever !! Seriously, it does matter !!

 

[grantsburg]

Originally Posted By: BurrWinder

Yes, the "newer stuff" with precious metal plugs and DIS or COP (Coil on plug/near plug) will still "run" with stock plugs to well after 100k, as the whole idea is to let them live as long as possible - BUT cylinder efficientcy, stress on the ignition system, engine management richening to compensate MEANS they still need to be replaced at like 100K or you are just missing the point. Yes, it's not like "cap,rotor wires or god forbid, points days, but the [censored] still doesn't last forever !! Seriously, it does matter !!


I can't disagree with anything you wrote there and I can see that my "Changing spark plugs is a thing of the past' was a lofty comment to make.

But I just wanted to point out that you can push plugs long past 100k and not really suffer from it because the ECU can adjust for it. Maybe a little more wear and slightly less mileage as a result, but if money is tight and you don't plan on going too far past 100k, I wouldn't bother to change plugs.

As to my Avenger, I didn't plan on keeping it as long as I have and at this point I wouldn't even attempt to change the plugs as I imagine they are pretty much welded in the block by this point.

 

[Astro14]

Originally Posted By: chrisri
Originally Posted By: Astro14
Originally Posted By: chrisri

Performance plugs use more fragile copper wire and tip for stronger spark. Thinner wire and tip will reduce resistance so spark will be stronger. This is why they do not last as long.


Uh...no.

All plugs use copper cores for good conductivity. The variances are in: electrode material, heat range (insulator length), and gap.

Harder/higher temp electrode materials last longer. Iridium has the highest melting point, then platinum, then the nickel steel of "copper" plugs.

Gap and temp range vary by application. Air is resistant to electricity, so a larger gap = more resistance and larger spark.

As far as life, that depends on application as well. I've seen 100K Iridium plugs that had no electrode left. None. How the engine ran with a gap at least twice as large as designed is beyond me, but it sure ran better with new plugs.

Even with Iridium tips, my Volvos show noticeable wear at 30K and run better with new plugs changed at that interval.

Mercedes plugs for the S600, also Iridium, are supposed to be changed at 100K...but I won't wait that long...


And were did i wrote that all plugs do not use copper core? Read my previous post.


I read your post. You stated that cooper plugs have a copper "tip".

Your description was wrong. There are no plugs that use copper as electrode material. The melting point is too low. The electrode material in what you refer to as "copper" plugs is, in fact, a nickel steel alloy.

However, all plugs use copper as a conductor.

http://www.ngksparkplugs.com/pdf/dyk_5points.pdf

 

[chrisri]

Originally Posted By: Astro14
Originally Posted By: chrisri
Originally Posted By: Astro14
Originally Posted By: chrisri

Performance plugs use more fragile copper wire and tip for stronger spark. Thinner wire and tip will reduce resistance so spark will be stronger. This is why they do not last as long.


Uh...no.

All plugs use copper cores for good conductivity. The variances are in: electrode material, heat range (insulator length), and gap.

Harder/higher temp electrode materials last longer. Iridium has the highest melting point, then platinum, then the nickel steel of "copper" plugs.

Gap and temp range vary by application. Air is resistant to electricity, so a larger gap = more resistance and larger spark.

As far as life, that depends on application as well. I've seen 100K Iridium plugs that had no electrode left. None. How the engine ran with a gap at least twice as large as designed is beyond me, but it sure ran better with new plugs.

Even with Iridium tips, my Volvos show noticeable wear at 30K and run better with new plugs changed at that interval.

Mercedes plugs for the S600, also Iridium, are supposed to be changed at 100K...but I won't wait that long...


And were did i wrote that all plugs do not use copper core? Read my previous post.


I read your post. You stated that cooper plugs have a copper "tip".

Your description was wrong. There are no plugs that use copper as electrode material. The melting point is too low. The electrode material in what you refer to as "copper" plugs is, in fact, a nickel steel alloy.

However, all plugs use copper as a conductor.

http://www.ngksparkplugs.com/pdf/dyk_5points.pdf

Poor use of words on my part. What i meant is performace plugs use different copper core wire. Plug tip are thinner in performance plugs but off course they are not made from copper.

 

[chrisri]

Poor use of words on my part. I meant performance plugs use different core copper wire. Tips on plugs are not made of copper, but they are thinner on performance plugs.