Denso 3515 Spark Plug

Denso Iridium Long Life Spark Plug for OE Fitment

Denso 3515 is an Iridium Long Life spark plug built for secondary ignition service in select Lexus performance applications. It is engineered to meet OE performance, durability, and emissions standards, with an iridium center electrode and a platinum needle ground design for stable ignition performance.

Compatible With Lexus IS500, Lexus LC500, Lexus RC F, and Lexus GS F applications listed below, this Denso Iridium Long Life (SIP) plug is a direct-fit replacement for OE-style service. The Denso 3515 part number is also referenced by Toyota 90919-01279 and Denso Auto Parts FK20HBR-J8.

Key Features

• Iridium center electrode tip material for precise spark delivery
• Platinum needle ground electrode tip design
• Needle-to-needle ground configuration
• Nickel ground electrode core material and copper center electrode core material
• 5000 ohm resistance
• Pre-gap size: 0.8
• 14.00 mm thread diameter, 26.50 reach, 16.0 hex size
• Flat seat type with manufacturer heat range 20
• OE-style spark plug for secondary ignition service

Product Details

The Denso Iridium Long Life (SIP) line focuses on long-service ignition performance for vehicles that require OE-level spark plug specifications. This Denso 3515 spark plug uses an iridium firing tip, a platinum needle ground electrode, and a three-ground-electrode layout to support consistent ignition characteristics in the applications listed. For Lexus IS500, LC500, RC F, and GS F models, it matches the OE-style dimensions and electrical characteristics needed for proper engine operation.

Fits 2022-2023 Lexus IS500, N/A. Fits 2020-2023 Lexus LC500, N/A. Fits 2020-2023 Lexus RC F, N/A. Fits 2020 Lexus GS F, N/A. Fits 2016-2019 Lexus GS F, N/A. Fits 2018-2019 Lexus LC500, N/A. Fits 2015-2019 Lexus RC F, N/A.

Common Issues This Part Addresses

• Misfire caused by worn spark plug electrodes
• Hard starting from degraded ignition performance
• Rough idle related to inconsistent spark output
• Reduced fuel efficiency from weak combustion events
• Emissions concerns tied to aging ignition components

Installation Notes and Tips

Verify thread diameter, reach, seat type, and pre-gap before installation. Use the vehicle service specification for torque and gap verification, and inspect ignition coils and related secondary ignition components during replacement. Confirm application by model year and engine configuration before ordering Denso 3515.

Quality Assurance

Denso manufactures this spark plug to OE performance, durability, and emissions standards. The Denso 3515 cross-references Toyota 90919-01279 and Denso Auto Parts FK20HBR-J8 for the same application.