2026-10-08 · 5 min read
Subaru WRX Spark Plugs Malaysia
The FA20DIT uses four iridium spark plugs that should be replaced every 30,000–40,000 km — shorter than naturally aspirated engines due to the turbocharger's combustion demands. Using the wrong heat range plug on a turbocharged engine risks pre-ignition and knock, which the ECU compensates for by retarding timing and reducing power. Always use OEM-spec NGK or Denso iridium plugs, and inspect electrode condition at replacement to detect any signs of running rich from injector issues or oil consumption.
Subaru WRX Spark Plugs
- WRX FA20DIT spark plugs: iridium; replace every 60,000 km — turbo direct injection wears plugs faster than NA; do not extend to 100,000 km on FA20DIT
- WRX plug heat range: OEM NGK is correct for stock boost; if WRX has aftermarket tune with higher boost — run one step colder plug to prevent pre-ignition under higher combustion temps
- WRX plug gap: iridium plugs come pre-gapped; do not regap iridium — fine electrode tip can break; confirm gap matches FA20DIT spec (typically 0.7–0.8mm) before installation
- WRX misfire under boost: misfire is dangerous — can damage turbo and engine; if WRX has misfire, diagnose immediately; check plugs, ignition coils, and injectors; do not continue driving with misfires on boosted engine