Modern car ignition is dependent on the creation of a spark at exactly the right moment so that the fuel/air mixture in the engine can be efficiently converted into power.

Spark plugs create the high-voltage spark necessary whilst withstanding extremes of heat and pressure. The key component of a spark plug is the central electrode that carries the electric charge to the tip. With their high conductivity, high melting points, high temperature stability and corrosion resistance, platinum, rhodium and iridium are ideal for firing tips (the active components in the plugs).

Platinum electrodes have a higher durability than traditional copper electrodes. This enables manufacturers to reduce electrode diameter, which in turn decreases the voltage required. The high durability of platinum can also improve combustion performance over the life of the spark plug, reducing emissions.

The use of electrodes manufactured from iridium or rhodium alloy facilitates further reductions in electrode diameter and gains in durability. Where even greater strength and durability is required, such as in aircraft spark plugs, ruthenium is used.