Originally Posted by whitefox
To be truthful, gold is the best conductor for electronic components, but who can afford gold core spark plugs. Plus they would not last long in their true form. The problem with silver, it is a soft metal like gold and could burn out quicker. .
I'm sorry that's incorrect.
Silver has the higest conductance, lowest resistance, and highest thermal conductivity of any metal.
Melting points for copper/silver are aprox. 1900F and 1700 F, respectively. Since EGT's run several hundred degrees F below that, and actual sparkplug temps well below EGT - worries about it wearing away are pretty groundless.