High-Efficiency Spark Plug for Subaru Boxer Engines ⚡

Keep your Subaru starting fast, idling smooth, and pulling strong with this OEM-grade ignition plug. Built for tight boxer-engine bays, it delivers clean combustion, better fuel economy, and long service life. A fine-wire precious-metal tip lowers required voltage, while a copper core and ribbed ceramic insulator control heat and prevent flashover.

Why you need it

Fresh plugs restore sharp throttle response, stable idle, easy cold starts, and reduced emissions. They protect the catalytic converter and keep ignition coils from overworking.

How it works

Your coil sends high voltage through the plug. The spark jumps the calibrated gap, igniting the air‑fuel mix. Proper heat range lets the plug stay clean without overheating, ensuring consistent, reliable ignition cycle after cycle.

When worn or failed

• Hard starting, rough idle, and hesitation
• Misfires, loss of power, higher fuel use
• Check Engine Light and potential catalyst damage
• Coil stress and increased emissions

Pro tips for install

• Replace as a full set on a cool engine
• Use factory gap; do not file the fine tip
• Torque to spec and apply dielectric grease to boots

Compatibility

• Impreza
• Forester