Denso 3115 Spark Plug

Double Platinum Spark Plug

This Denso Double Platinum spark plug is built for OE-level performance, durability, and emissions control. It uses platinum on the center electrode and a platinum chip on the ground electrode for consistent ignition performance across a wide range of older import applications.

Key Features

• Double Platinum design with platinum on both electrodes for stable spark performance.
• 5000 ohm resistor helps control electrical noise in the ignition system.
• Pre-gapped to 1.1 mm for straightforward service replacement.
• Nickel ground core and copper center core support efficient heat transfer.
• Flat seat, 14 mm thread diameter, and 19.00 mm reach for confirmed fitment applications.

Product Details

Part number 3115 is a Denso spark plug from the Double Platinum line, engineered to meet strict OE standards for performance, durability, and emissions. The construction combines a platinum center electrode tip with a platinum chip ground design, along with a standard ground configuration and 20.6 mm hex size. This plug is used in a broad range of applications, including Hyundai Sonata, Mitsubishi Eclipse, and Subaru Loyale models listed in the fitment data. Part number 3115 is also cross-referenced to Denso Auto Parts P20PR11 for the same application.

Common Replacement Uses

• Restores weak or inconsistent spark output.
• Addresses misfire concerns caused by worn electrodes.
• Helps correct rough idle and hard starting linked to aged plugs.
• Supports proper combustion when service intervals have been exceeded.
• Replaces plugs with incorrect heat range, reach, or seat type.

Installation Notes

Verify thread diameter, reach, seat type, and pre-gap before installation. Confirm the application against the vehicle’s service information for the exact engine and ignition specification. Use the listed fitment data for Hyundai Sonata, Mitsubishi Eclipse, and Subaru Loyale applications, and match the plug to the required ignition setup before final installation.

Quality Assurance

Denso manufactures this Double Platinum spark plug to strict OE performance, durability, and emissions standards.