I have always used Iridium in all my cars as they are high performance plugs designed to handle advanced levels of tuning and still offer easy start ups and smooth idling. By utilizing a 0.4mm diameter Iridium plug electrode core and a V-shaped grooved electrode, lower voltage is required for the spark to occur, this delivers a stronger Ignition spark, they stabilise Idling, and reduce the likelihood of misfire during high boost. The HKS plug is designed to prevent detonation and misfiring.
here is the model number HKS (S40i) Super Fire Racing Iridium
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