Denso 5365 Spark Plug

Denso Iridium Power Spark Plug 5365

Denso Iridium Power spark plug 5365 is built for drivers who want precise ignition performance from a compact iridium design. It uses a 0.4 mm iridium center electrode to support consistent spark delivery, along with a tapercut and U-groove ground electrode profile for efficient flame initiation.

For buyers searching for a Denso spark plug for Honda Civic or Toyota Corolla ignition service, this part number 5365 is a direct-fit style option where the listed specifications match the application requirements.

Key Features

• Iridium Power line from Denso
• 0.4 mm iridium center electrode tip
• Tapercut, U-groove ground electrode tip design
• Slant ground configuration with one ground electrode
• 5000 ohm resistance
• Flat seat, 14.00 mm thread diameter, 19.00 mm reach
• 16.0 mm hex size and 0.9 pre-gap size
• Nickel ground electrode core and copper center electrode core
• Manufacturer heat range 24

Detailed Description

Denso Iridium Power 5365 is a performance-focused spark plug engineered around a fine-wire iridium center electrode. The small 0.4 mm tip reduces the firing demand at the plug gap, while the tapercut and U-groove ground electrode shape supports a cleaner spark path. The plug also uses a flat seat, 14.00 mm thread diameter, and 19.00 mm reach, making the dimensional details important for correct ignition service.

This Denso 5365 spark plug is a practical choice for maintenance on vehicles that call for this specification set, including select Honda Civic and Toyota Corolla applications. The DENSO Auto Parts interchange reference IU24A is listed for this same application.

What It Helps Address

• Hard starting caused by worn or fouled spark plugs
• Misfire conditions related to weak ignition output
• Rough idle from inconsistent spark delivery
• Reduced throttle response from degraded plug performance
• Service replacement needs for specified Honda Civic and Toyota Corolla ignition systems

Installation Notes and Tips

Verify thread diameter, reach, seat type, and heat range before installation. Confirm the gap specification against the vehicle service information, and inspect ignition coils, wires, and boots during spark plug replacement. Use the correct torque procedure for the cylinder head material and avoid over-tightening.

Compatible With select Honda Civic and Toyota Corolla applications where Denso 5365 specifications are required. Fits should always be confirmed by year, engine, and ignition system requirements before purchase.

Quality Assurance

Denso manufactures this Iridium Power spark plug to published dimensional and material specifications, including iridium center electrode construction and the stated resistance, reach, and heat range values. Part number 5365 is also referenced as IU24A in DENSO Auto Parts interchange data.