Ignition Coil and Iridium Spark Plugs for Subaru Legacy (2010-2012) 2.5L

OEM-Grade Ignition Coil and Iridium Spark Plug Kit for 2010-2012 Subaru Legacy

What it Does: Replaces degraded factory coil packs and worn spark plugs with matched direct-fit ignition components to eliminate misfires, stabilize idle, and restore primary spark energy.

The Stock Legacy Ignition Thermal Breakdown

Due to the horizontal layout of the Subaru Boxer engine, the ignition coils sit in tight proximity to the cylinder heads and exhaust manifolds. Over time, extreme thermal cycling degrades the factory silicone boots and cracks internal epoxy insulation. This leads to dielectric breakdown, secondary winding resistance drift, and high-load spark blow-out, while standard plugs experience gap erosion that overworks the primary ignition circuit.

The Engineering Solution

This service kit pairs four direct-fit coil-on-plug units featuring high-dielectric epoxy potting and heat-resistant silicone boots with four fine-wire iridium spark plugs. The high-temperature copper windings deliver consistent high-voltage output under load, while the 0.6mm iridium center electrodes drastically lower voltage demand, resist fouling, and ensure sharp flame front propagation in EJ253 combustion chambers.

Technical Specifications

Compatibility

• 2010-2012 Subaru Legacy 2.5i (2.5L H4 SOHC)
• 2010-2012 Subaru Legacy 2.5i Premium (2.5L H4 SOHC)
• 2010-2012 Subaru Legacy 2.5i Limited (2.5L H4 SOHC)

The Subaru Boxer Caliber

Engineered to handle the distinct thermal profile of Subaru boxer platforms, this ignition package delivers precise spark timing and robust arc duration to maintain clean combustion, crisp throttle response, and smooth power delivery across the entire rev range.