Well that make cents! i thought i was colder than stock........shows how much i know.:BangHead:
The cross reference chart i found says my plug crosses over to a RN11YC
Haven't found the cross from your suggested C63YC...............
That's why I don't like cross reference charts because there is too much fudge room. I always consult my trusty Champion catalog. I really need to get an NGK and Autolite catalog so I can reference them.
You could really be at an 11 heat range in a Champion plug. The cross reference I used said 9 but your plug looks plenty hot.
