# How to read your spark plugs

**URL:** <https://forums.speedlife.net/t/how-to-read-your-spark-plugs/144777>\
**Category:** Canada Nissan Automotive\
**Created:** [October 19, 2006, 10:43pm UTC](https://forums.speedlife.net/t/how-to-read-your-spark-plugs/144777 "2006-10-19T22:43:24Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Nis240](https://avatars.discourse-cdn.com/v4/letter/n/a9a28c/32.png) [@Nis240](https://forums.speedlife.net/u/Nis240)\
**Post date:** [October 19, 2006, 10:43pm UTC](https://forums.speedlife.net/t/how-to-read-your-spark-plugs/144777/1 "2006-10-19T22:43:24Z")

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> **[{{ title }}](http://www.ngksparkplugs.com/about-ngk/faqs/spark-plug-faqs/how-do-i-read-a-spark-plug)**
>
> {{ desc}}

  
Lots more interesting stuf on the site such as heat range, and more info about detonation and what kind of spark plug to use.

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**Author:** ![gotboom](https://avatars.discourse-cdn.com/v4/letter/g/94ad74/32.png) [@gotboom](https://forums.speedlife.net/u/gotboom)\
**Post date:** [November 28, 2006, 11:26am UTC](https://forums.speedlife.net/t/how-to-read-your-spark-plugs/144777/2 "2006-11-28T11:26:26Z")

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I ran into the same issue with my fairlady. The heat factor on my plug was 6. The dealer had from 3 to 6 avail. The last digit on the plug determined the heat factor. :drinkers: