Sparkplug Life
#1
Instructor
Thread Starter
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RE Denso Iridium Long Life (w/ 0.7mm electrode - SK20R11)
Just checked wife's RX w/100k miles and plugs have same .043 gap they had when brand new. Plugs look good and car is running fine.
Several have reported on this forum similar observations with plugs having 125k+ miles. I am asking myself will these plugs ever wear out? Do they ever need to be replaced due to normal wear and tear? Denso will only warranty these plugs for 100k miles although their website mentions the fact that Toyota says they can go 120k miles.
I found a paper that Denso presented to the SAE. It claims this plug was developed to go 200k miles and their research shows they will "easily" do that.
http://www.sparkplugs.com/pdfs/iri.pdf
Interesting reading!
Just checked wife's RX w/100k miles and plugs have same .043 gap they had when brand new. Plugs look good and car is running fine.
Several have reported on this forum similar observations with plugs having 125k+ miles. I am asking myself will these plugs ever wear out? Do they ever need to be replaced due to normal wear and tear? Denso will only warranty these plugs for 100k miles although their website mentions the fact that Toyota says they can go 120k miles.
I found a paper that Denso presented to the SAE. It claims this plug was developed to go 200k miles and their research shows they will "easily" do that.
http://www.sparkplugs.com/pdfs/iri.pdf
Interesting reading!
Last edited by artbuc; 09-22-09 at 11:22 AM.
#2
Lexus Champion
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RE Denso Iridium Long Life (w/ 0.7mm electrode - SK20R11)
Just checked wife's RX w/100k miles and plugs have same .043 gap they had when brand new. Plugs look good and car is running fine.
Several have reported on this forum similar observations with plugs having 125k+ miles. I am asking myself will these plugs ever wear out? Do they ever need to be replaced due to normal wear and tear? Denso will only warranty these plugs for 100k miles although their website mentions the fact that Toyota says they can go 120k miles.
I found a paper that Denso presented to the SAE. It claims this plug was developed to go 200k miles and their research shows they will "easily" do that.
http://www.sparkplugs.com/pdfs/iri.pdf
Interesting reading!
Just checked wife's RX w/100k miles and plugs have same .043 gap they had when brand new. Plugs look good and car is running fine.
Several have reported on this forum similar observations with plugs having 125k+ miles. I am asking myself will these plugs ever wear out? Do they ever need to be replaced due to normal wear and tear? Denso will only warranty these plugs for 100k miles although their website mentions the fact that Toyota says they can go 120k miles.
I found a paper that Denso presented to the SAE. It claims this plug was developed to go 200k miles and their research shows they will "easily" do that.
http://www.sparkplugs.com/pdfs/iri.pdf
Interesting reading!
#3
Lexus Test Driver
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I changed my daughters plugs when we got her 99 at 115K. They looked pretty good, but I figured they couldn't be performing like they did as new. I replaced them (no simple task!!), but I figured why not have a new set for the next 100,000 miles! I'd replace them since you have them. I know they're not inexpensive, but our labor is cheap!
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
#4
Instructor
Thread Starter
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I changed my daughters plugs when we got her 99 at 115K. They looked pretty good, but I figured they couldn't be performing like they did as new. I replaced them (no simple task!!), but I figured why not have a new set for the next 100,000 miles! I'd replace them since you have them. I know they're not inexpensive, but our labor is cheap! ![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
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#8
Instructor
Thread Starter
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Me too!!! I just pulled the front guys. I pulled the backs at 75k or so just to put anti-sieze on them based on a horrible experience my neighbor had with her Sequoia which was only 5-6 years old. Dealer was doing some troubleshooting and discovered a plug was siezed and they broke the head trying to get it out. Led to a major engine overhaul which dealer would NOT accept any responsibility for. What a story. Dealer said plug was melted - no kidding. Ever hear of a melted plug?
No way I wanted to go 13-14 years without pulling/inspecting plugs!
#9
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Man, now I feel like a donkey... I had mine replaced at 54K and recently 125K at dealer... so basically I threw away two sets of plugs that were probably 1/3 through their life only.
![Frown](https://www.clublexus.com/forums/images/smilies/frown.gif)
#10
Lexus Champion
#11
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![Crying](https://www.clublexus.com/forums/images/smilies/Peace.gif)
I'd like to think that Lexus is more honest than QuikLube and that my additional $95 in parts and labor was put to actual use on my car...
![Big Grin](https://www.clublexus.com/forums/images/smilies/biggrin.gif)
If not, I used up a good $23 in fuel, so there Lexus...
![Stick Out Tongue](https://www.clublexus.com/forums/images/smilies/tongue.gif)
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