Iridium Sparkplug

Using google:

Iridium spark plug specifications and benefits
Relatively recent advances in fabrication techniques have enabled the use of Iridium - an incredibly hard precious metal, for the construction of spark plug electrodes. Laser technology is used to weld the Iridium tip to spark plugs manufactured by both Denso and NGK. It's worth noting that spark plugs can't increase the potential power that an engine can generate but a more efficient spark will provide more efficient combustion and associated performance and economy benefits. A poor spark from a worn or low grade spark plug will reduce efficiency. An Iridium plug will produce a more efficient spark. ]

If you are running anything that requires frequent plug changes (bikes) IMO they are not worth the money. Of course, I don't ever buy NGK because they aren't available locally, and I can't tell a difference between Autolite $2 plugs and NGK $8 plugs. The air screw makes more difference to me....

Platinum and Iridium plugs were designed for one purpose....

JD Powers 36 month "Cost of Ownership" ratings.

Automakers didn't start building engines that require tune-ups every 100,000 miles instead of every 20,000 for their health... They did it because most owners will travel somewhere between 30 and 90k during first the 3 years that they own their vehicle.

Delay the first tune-up, coolant change, and trans fluid change until after that and you've reduced the cost of ownership by as much as $1,000.

Of course, replacing Dexcool, Iridium plugs, and long-life trans fluid costs 4x as much as the old parts/chemicals... the cost of ownership over 5 years is probably relatively unchanged.


A lot... and I mean literally hundreds, of people I've chatted with claim that Iridium improves performance.
Ya... A new plug WILL improve performance over an old plug. Swap equally rated new copper and iridium plugs back and forth and you'll see no difference on the dyno.