Precious metal spark plugs
Iridium spark plugs
Iridium spark plugs from NGK currently represent the highest-quality technological solution. They have an iridium-alloy tip on the middle electrode. It is welded on in a special process using a laser.
The precious metal iridium is one of the world's hardest metals. It starts melting at a temperature of 2450 °C and is very resistant to spark erosion. Through its use, the service life is doubled on average in comparison to standard spark plugs.
In addition, the precious metal allows the middle electrode to be designed significantly thinner, with a thickness of 0.6 mm. These measures reduce the ignition voltage requirement considerably and contribute to improving the spread of the flame front in the combustion chamber.
Platinum spark plugs
With these spark plugs a platinum plate on the middle electrode ensures a more constant output of the spark plug over the entire service life - even under difficult conditions. Based on its narrow middle electrode, this spark plug emits very little spark voltage, it discharges the ignition coils and ensures for optimal combustion all the way to the outer areas of the combustion chamber.
The self-cleaning effect of iridium spark plugs
Regardless of the current operating temperature, electrical discharges take place in the ring gap between the middle electrode and insulator. They remove any carbon particles and thereby guarantee that the ignition voltage is not conducted.