On the platinum-tipped and iridiumtipped spark plugs, the center electrode and the opposing ground electrode are covered with a thin platinum or iridium tip. Therefore, these spark plugs provide a longer service life than conventional spark plugs. Because platinum and iridium resist wear, the center electrode of these spark plugs can remain small and offer excellent sparking performance.
1. Platinum-tipped spark plug
On the platinum-tipped spark plug, platinum is welded onto the tip of the center electrode and the ground electrode. The diameter of the center electrode is smaller than in the conventional spark plug.
2. Iridium-tipped spark plug
On the iridium-tipped spark plug, iridium (which provides a higher wear resistance than platinum) is welded onto the tip of the center electrode, and platinum is welded onto the ground electrode. The diameter of the center electrode is smaller than in the platinum-tipped spark plug.
Some of these plugs do not have platinum welded onto their ground electrodes.
The platinum-tipped and iridium-tipped spark plugs must be replaced at the specified intervals. They do not require the plug gap adjustment or cleaning between replacements if the engine is running properly.
Platinum- and iridium-tipped spark plug replacement intervalsEvery 100,00to 240,000km The replacement intervals may vary by vehicle model, engine specifications, and area of use.
To prevent the electrodes from being damaged, do not clean platinum- or iridium-tipped spark plugs. Cleaning will damage the electrodes and will inhibit the full ability of the spark plugs. However, if the electrodes are sooty or excessively dirty, they may be cleaned for a short period of time (2seconds maximum) in a spark plug cleaner. The gap of these spark plugs does not require adjustment except when installing as new. The illustration on the left shows the type of caution label that is affixed in the engine compartment of a vehicle using platinum- or iridium-tipped spark plugs.