Denso 5317 Spark Plug

Denso Iridium Power Spark Plug 5317

Denso Iridium Power spark plug 5317 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 tapered-cut, U-groove ground electrode profile for efficient flame initiation.

The Iridium Power line focuses on fine-wire electrode construction and stable ignition characteristics for modern engines that demand accurate spark control. For shoppers searching Denso spark plug 5317, IW27 cross reference, or an OE-style iridium spark plug for Honda Civic applications, this part delivers a technical upgrade in the secondary ignition system.

Key Features

• Iridium center electrode tip material for fine-wire spark performance
• 0.4 mm center electrode diameter for concentrated ignition energy
• Tapercut and U-groove ground electrode tip design
• 5000 ohm resistance for ignition system noise control
• Copper core center electrode and nickel ground electrode core
• Flat seat design, 14.00 mm thread diameter, 19.00 mm reach
• Pre-gapped to 0.7 mm
• Manufacturer heat range 27

Detailed Description

Denso 5317 is an Iridium Power spark plug engineered around a small-diameter iridium center electrode and a single-ground-electrode layout. The fine-wire tip helps concentrate the spark, while the tapered-cut and U-groove ground design supports efficient ignition across a wide range of operating conditions. With a 20.6 mm hex, flat seat, and 19.00 mm reach, this plug is built to match the dimensional requirements of specific engine applications. This part cross-references DENSO Auto Parts IW27 for the same application.

What It Helps Address

• Hard starting caused by worn or inconsistent spark plugs
• Misfire conditions related to degraded ignition performance
• Rough idle from weak spark delivery
• Reduced throttle response from inefficient combustion
• Ignition noise concerns where resistor plugs are specified

Installation Notes and Tips

Verify thread diameter, reach, seat type, and heat range against the engine specification before installation. Check and confirm the pre-gap setting against the vehicle service manual, and inspect ignition coils, wires, and boots for wear before fitting new plugs. For Honda Civic spark plug replacement searches and other Denso 5317 fitment research, always confirm the exact engine application before ordering.

Quality Assurance

Denso manufactures the Iridium Power line with fine-wire iridium electrode construction and OE-focused dimensional control. Part number 5317 is identified by Denso as IW27 in interchange listings.