NGK IRIDIUM IX advantages: - Iridium centre electrode (0.6mm diameter). - Better ignition with less power needed. - Higher performances compared to classic spark plugs. - Taper Cut ground electrode (Better flame spread). - 2 to 3 times more lifetime in comparison with standard plugs. - Better stability. - Less fuel consumption. - Stronger accelerations / More reaction from the engine. - Corrosion proof alloy. - Cleaner combustion / Less unburned fuel. - Easier cold start. - Smooth Idle / Less vibrations.