Spark plugs

Discussion in 'Dodge Challenger General Maintenance' started by Larry St Denis, Sep 22, 2021.

  1. Sep 22, 2021 at 3:30 PM #1
    Larry St Denis

    Larry St Denis Full Access Member

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    I didn’t see this question any where else, what kind/type of spark plug is preferred by any of you for the 392 motor?
     
  2. Sep 22, 2021 at 4:25 PM #2
    Wizard of Iz

    Wizard of Iz Full Access Member

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    Quick Google search says that the Mopar spark plug is part number SP149212AC

    I'm pretty sure it's a NGK Laser Platinum plug. My notes say that the NGK plug is LZTR6AP11EG


    I'm still 70,000 miles away from needing to change them.
     
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  3. Sep 22, 2021 at 4:58 PM #3
    SRT-Tom

    SRT-Tom Well-Known Member Staff Member Super Moderator Article Writer

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    Last edited: Sep 22, 2021
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  4. Sep 22, 2021 at 5:18 PM #4
    Larry St Denis

    Larry St Denis Full Access Member

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    Is anyone using anything else with positive results?
     
  5. Sep 23, 2021 at 10:59 AM #5
    Larry St Denis

    Larry St Denis Full Access Member

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    Guess not, lol. NGK also makes an iridium plug for the 392 that is supposed to have better longevity than the platinum model. I went with Ruthenium on my Ram 5.7 since they are a huge pain in the a$$ to change. Oem champion copper plug has a 30000 mile replacement interval and I know from a bad experience they don’t last for 2 intervals. Hemi engines are really hard on plugs and the only plug I’ve found more durable than the original for the 392, so far, is the iridium. I’m not due to change mine for a little while yet but I would like to have the most amount of info before I get there.if Ruthenium was available for the 392 I wouldn’t hesitate to use that. Have had them in my Ram for 2 years now and they have performed extremely well.
     
  6. Sep 23, 2021 at 1:36 PM #6
    Cloverdale

    Cloverdale Full Access Member

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    I've successfully cleaned and reused even iridium plugs. Though recommended for iridium plugs due to their brittle / sensitive center electrode there is a risk of using the pictured style gap tool as it can easily result in pushing the center electrode down into the body of the plug perhaps rendering it unusable. stm-spark-plug-gapper-tool-12-mm_1024x1024.jpg
     
  7. Sep 23, 2021 at 7:55 PM #7
    Hopslayer

    Hopslayer Full Access Member

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    I switched to a cooler plug after adding a supercharger. Supposedly, for the supercharger I added and my Pentastar engine, this is the best spark plug available.

    70C63BAF-8AF7-4D8C-9F24-BD2E95DB00D2.png
     
  8. Sep 24, 2021 at 8:20 PM #8
    2017 Redline HC

    2017 Redline HC 2021 Durango RT

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    I was looking at where the coils and plugs are located on my HC. I thought my RT was a bitch to change plugs on….the HC looks like an ignorant job.