Ok guys bare with me here. I have a few questions about spark plugs in genereal.
If a plug is too cold, it will foul easily, right?
If a plug is fouled, that means it misfires, right?
When your car/truck is misfiring, does that cause any damage or do you just get bad performance?
How can I tell if one of my plugs is misfiring/fouled?

and this last one is not really related to plugs but...

Can I rely on autotaps "Total Spark Plug Misfires" to tell me if my plugs are really misfiring or not.

thanks, i know these are beginner gear head questions but I had to piece together all of this car info my self and wasnt taught all of the basics.

 

Looks like a good place to post my questions also...

1. What makes a plug "cold"?
2. What makes a plug "hot"?

Please excuse my ignorance

 

Yes, a colder plug 'may' foul and or misfire at lower rpms. That's what my BR7s do so I turn the o/d off in town. You will feel the slight misfire at idle--more so when under load. It completely smooths out as rpms climb--see sig for track results. No harm is caused by a colder plug whereas, a hotter plug can lead to detonation.................

Having said that, I pulled my no. 1 plug Sun. after 17,000 miles of use and it was not fouled--no visible deposits--with a 'perfect' tannish-grey porcelain color. This was not exactly the proper way to read a plug in that you really need to shut down immediately after a WOT run to get the best reading but mine will do. Sorry, I d/k anything about Autotap.

What makes a plug 'cold' or 'hot' is the design of the center porcelain primarily. The 'shorter' the porcelain is, the quicker the combustion heat can be fed off to the coolant passages. Hotter plugs, typically will have a longer center electrode/porcelain.

http://www.ngksparkplugs.com/techinf...s/overview.asp

Dan