Spark plug failure due to a combination of strong magnetic fields and undesirable fuel additives

(in lingua inglese)

The case presented here is economically important because early engine failure has a nefarious effect on brand reputation. It exemplifies the fact that failure and fracture are different terms and is a rare case where electromagnetic phenomena cause the failure of a mechanical system. The strong magnetic field in the high-efficiency spark plug deposits excessive amounts of metallic ions on the insulator where they cannot be burned off. This creates a shortcircuit, leading to inefficient combustion and deposition of soot on the insulator surface. If high-quality fuel is used, insufficient metal ions are present to initiate the process, but organometallic anti-knocking agents in low-grade fuel acerbate the effect and provoke failure.