Spark Plugs

Precious Metal

  • Overview
  • Analysis
  • Electrode Gap
  • Electrode Gap Adjustment
  • Projection
  • Modified and Performance Engines
  • Heat Range
  • Operating Temperature
  • LPG Compatibility
  • Precious Metal
  • Installation
  • Resistor Spark Plugs
  • Racing Spark Plugs

NGK’s range of precious metal spark plugs provide two major benefits over conventional spark plugs:

  • High Ignitability – is only achieved by utilising an exposed fine tip centre electrode allowing for superior flame growth.
  • Long Service Life – is achieved by utilising a high percentage of precious metals patented by NGK.

As emission laws become more stringent, the performance expectations of spark plugs also increase. NGK have developed a range of Iridium and Platinum spark plugs to meet and surpass the modern requirements of vehicle manufacturers.

Precious metals such as Iridium and Platinum have much higher melting points over traditional metals such as Nickel.

  • Iridium – 2410°C
  • Platinum – 1772°C
  • Nickel – 1453°C

This allows centre electrode diameters to reduce from 2.5mm using Nickel, to 0.6mm using Iridium or Platinum. The finer point means that once a spark forms, the flame kernel does not have a large mass of centre electrode that reduces absorption of heat and the flame shadow impeding the flame progress. This equates to a more complete burn that translates to:

  • Improved acceleration
  • Improved fuel consumption
  • Smoother idling