Is the main advantage to a colder heat range plug simply to reduce pinging? It seems like from what I have read that the warmer heat range plugs will produce a hotter spark obviously, give a more complete combustion, and reduce carbon deposits from building up, but I see a lot of guys who have gone to colder heat range plugs like autolite 3923's. If you don't have problems with pinging shouldn't you use the warmer heat range plugs? Will having a colder temp stat and/or a programmer impact that decision?

 

If you do short trips in city like driving a hotter plug makes sense,
but only if you feel your engine missing.

Dodge has always specified colder heat range sparkplugs for the V10 which doesn't have to meet all the tougher emissions testing because it is in the 2500/3500 heavy truck category. This is a clue that the standard factory sparkplugs for 3.9/5.2/5.9 is already pretty hot, about 3 steps hotter than used in the V10 or in 1980's era Chrysler engines.

More than you ever want to know about Magnum engine Sparkplugs:

http://makeashorterlink.com/?D10022B5D

 

I guess I am trying to figure out why some people have gone to a colder plug than what is factory recommended. Is it mainly because of detonation problems or are there some other benefits?