Technical? Well, do we need a scientific diseration, which I am not capable of. Or, perhaps we could read a few scapes from vendor sites, which sell coppper, platinum and iridium plugs (me wonders why they would manufacture these types of plugs if they are hype - but I digress):
From ACDelco regarding iridium:
"ACDelco, an important player in the 'aftermarket' for the automotive industry, has released a new high-performance spark plug, which uses the platinum group metal iridium.
The ACDelco Professional Iridium Plug is the latest in a range of products the company prides itself on having developed for all types of vehicles, reports Autofan.com.
ACDelco spark plugs product specialist Michelle Glazier said: 'Iridium is one of the strongest, densest precious metals on earth. And with a 100,000-mile limited warranty offered by ACDelco, customers can be confident that these spark plugs are built to last.'
The plugs boast a melting point 700 degree Celsius higher than that of platinum, and are therefore able to burn fuel more efficiently and deliver better performance. They also require less precious metals for the electrodes than platinum-tipped plugs.
'If you look at an iridium tip, it's equivalent to about the size of two pinheads', said Ms Glazier. 'It's less drain on the electrical system because it's smaller, and it's a more efficient use of the energy in your vehicle.'
Specially designed electrodes increase electric field strength and reduce sparking voltage, which results in better cold starting and quick acceleration. They also offer enhanced flame spread during combustion, with a secondary microdischarge on the centre electrode that burns off carbon deposits and ensures improved antifouling performance."
From a European racing website (just in case you are French - Canada you know):
"Because of the properties of Iridium, the spark plugs centre electrode can be made with a much smaller diameter than with platinum types (usually 0.8mm for NGK and 0.7mm for Denso), Gold or gold palladium and copper/nickel types. This means that spark plugs potential difference is more concentrated and hence less 'spark jump' voltage is required - this can be as much as 5,000 volts less than with standard plug types. Ignition is improved and less strain is placed on the ignition system. Benefits of improved ignition/combustion include better fuel economy, increased power/acceleration and especially better throttle response."
But, this is boring....
