This answer depends on the priorities of the driver or rider. Iridium, on one hand, is six times harder and eight times stronger than platinum and has a melting point of 698°C higher. Platinum, however, is a less cost intensive material that still offers significantly better durability than standard nickel plugs. With NGK SPARK PLUG’s Laser Iridium range, the positives of both precious metals can be enjoyed since this type of plug features an iridium centre electrode and a platinum ground electrode.