NGK Iridium IX Spark Plugs represent the ultimate evolution of spark plug technology and performance. Iridium is significantly stronger than any metal used in spark plugs today. Its also the hardest metal used, which allowed NGK engineers to design an ultra fine center electrode; reducing the voltage requirement for Spark.
The design of the ultra-fine center electrode is designed not too thin to ensure maximum durability and life of the spark plug, and not too thick for an accurate and consistent spark.
Iridium IX delivers the performance and durability to meet the demands and expectations of those who expect nothing but the best.
The NGK 2315 Iridium is 2 steps colder than stock heat range plugs (NGK 2313 and NGK 5306) in the 5.7 Hemi Ram and one step colder than the NGK 2314 and NGK 4306. .- good for big shots of Nitrous and forced induction. This is for a set of 16 spark plugs.