The Denso Iridium spark plug is a new generation of high-performance spark plug that uses the world’s smallest Iridium electrode that is a mere 0.4 mm in diameter.  The smaller electrode is able to concentrate the electric potential at the electrode resulting in a stronger electric field.  The stronger the electric field, the less voltage is required to create a spark.  The result is good combustion for all types of driving, the engine starts easily, and acceleration improves.

These plugs are also one step colder than stock, meaning that they are better able to dissipate heat, and are perfectly suited to a modified engine.