FAO Tom - Spark Plugs

[Anonymous]

Tom,

Can you shed any light on the materials used for electrodes and their benefits?


Silver
Yttrium
Iridium

 

[Tom]

Who uses silver and yttrium?

The idea is to make the electrode harder and wear down less meaning longer service intervals. (note, not better performance) But most of them still seem to have steel/copper earth electrodes.

 

[Anonymous]

Bosch do an Yttrium plug.

Silver - you read that most racing plugs consist of a silver centre electrode.

The Bosch super 4's use a silver plated elecrode. I have also seen the Bosch super Yttrium spark plug.

Just wondering which one is the better spark plug.

 

[Tom]

They all do the same job and when they wear they don't do a good job.

A new cheap plug will always be better than a worn out very expensive plug.

Remember the spark plug is only one part of the ignition system.