[MIke L]

Originally Posted by HWYSTR455

It was kind of insinuated, but if you look at cross reference charts you will be able to see it.

This is the thread I made similar comments on:

https://forums.maxperformanceinc.com...=885230&page=2

So an XR5 plug roughly translates to an AC R45S, and an XR4 roughly translates to a AC R43S. The AC R44S falls in the middle.

https://ngksparkplugs.com/wp-content...rence_2019.pdf

When you say '2-steps colder' it has a different meaning in one brand than some others. That's the point I was trying to make.


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Thanks,
I thought the XR4 was eq to the ac R45 and the XR5 eq to AC 43/44. at least that’s what I’ve been reading.

Thanks for replying

Mike