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

• Spark plugs designed for optimal durability failed after 100 h of operation.
• The insulator was covered with a deposit consisting of iron oxides and soot.
• The strong magnetic field deposits metal ions on the insulator.
• Organometallic anti-knocking agents in low-grade fuel acerbate the effect.
• Government action imposing compliance with fuel composition norms is essential