Denso 5731 Spark Plug

Denso Iridium Racing Spark Plug 5731

Denso Iridium Racing 5731 is a race-focused spark plug built for serious ignition demands. It combines an iridium center electrode with a copper core and a platinum-tipped ground electrode for stable spark delivery in high-output applications.

For buyers searching for a Denso spark plug for performance tuning, Denso 5731, or an iridium racing spark plug for Honda Civic and Toyota Corolla builds, this part is positioned for precise secondary ignition service where heat control and consistent firing matter.

Key Features

• Iridium center electrode tip for fine-wire spark delivery
• Copper center electrode core for efficient heat transfer
• Full platinum ground electrode tip design
• Single slant ground configuration for focused spark exposure
• 5000 ohm resistance for ignition system noise control
• Pre-gapped to 0.6 mm
• 12.0 mm thread diameter, 19.0 mm reach, and 16.0 mm hex size
• Flat seat design for applications that specify a gasket-style plug
• Manufacturer heat range 27 for performance-oriented thermal control

Product Details

The Denso Iridium Racing line is aimed at demanding street and track use where ignition consistency is critical. Part number 5731 uses an iridium center electrode to support a concentrated spark, while the platinum ground tip and nickel ground core help maintain durable electrode geometry under repeated firing. The copper core construction supports heat dissipation, which is important in engines that see sustained load or elevated cylinder temperatures.

This spark plug is a strong match for performance-minded maintenance searches such as Denso 5731 spark plug replacement, iridium racing spark plug for Honda Civic, and performance spark plug for Toyota Corolla ignition service. This part cross-references DENSO Auto Parts (e.g., IXU01-27) for the same application.

Common Issues It May Address

• Misfire caused by worn or eroded spark plug electrodes
• Hard starting from inconsistent ignition output
• Rough idle related to degraded spark quality
• Loss of throttle response from weak combustion events
• Ignition noise concerns in performance electrical systems

Installation Notes

Verify thread diameter, reach, seat type, and heat range before installation. Confirm the plug gap matches the engine specification if your application requires a different setting than the pre-gap size. Use the correct 16.0 mm spark plug socket and follow the vehicle manufacturer’s torque specification to avoid thread or seat damage.

Compatible With applications that specify a 12.0 mm thread, 19.0 mm reach, flat seat, and 0.6 mm pre-gap. For Honda Civic and Toyota Corolla service, confirm the engine code and ignition specification before ordering Denso 5731.

Quality Assurance

Denso manufactures this Iridium Racing spark plug to support performance ignition service with specified electrode materials, resistance, and dimensional accuracy. The listed construction details provide a clear reference for parts matching and product-rich search results.