Hot and Cold spark plug.

[Fernando Mendes]

What are the advantages between the hot and cold spark plug? In which situations(trip or stroll)do you use them?

[greg g]

I remember folks putting hoter plugs in older engines that were prone to oil fouling from worn rings or cylinders.  The belief being that a hotter plug tip would help cook off carbon lessening misfire.  As far as cold plugs, people who were chasing, pinging, spark knock or pre ignition used them in the belief that a cooler tip would not act like a diesel glow plug lighting the air fuel mix before it was fully compressed.  Spark plug heat range is not a reference to the quality, length or intensity of the spark.

 

https://www.ngkntk.in/importance-of-heat-range/

Edited August 26, 2023 by greg g