Denso 5375 Spark Plug

Denso Iridium Power Spark Plug 5375

The Denso Iridium Power 5375 spark plug is built for drivers who want precise ignition performance and stable combustion response. It uses a 0.4 mm iridium center electrode to promote efficient spark delivery, along with a tapercut and U-groove ground electrode design for consistent firing characteristics.

Compatible With 1988-1991 BMW M3, 1988 BMW M5, and 1987-1988 BMW M6, this spark plug is a direct-fit ignition service part for select BMW performance applications. The Denso 5375 is also cross-referenced to BMW 12 12 1 311 928 and DENSO Auto Parts IX22B for the same application.

Key Features

• Iridium Power line with a fine-wire 0.4 mm iridium center electrode
• Tapercut, U-groove ground electrode tip design for focused spark exposure
• 12 mm thread diameter, 19.00 mm reach, and flat seat design
• Pre-gapped to 0.9 for select BMW ignition applications
• 5000 resistance specification for ignition system compatibility
• Nickel ground electrode core with copper center electrode core

Product Details

Denso Iridium Power spark plugs are engineered for precise ignition performance in demanding street and performance use. Part number 5375 combines an iridium center electrode with a copper-core center and nickel-core ground electrode to support reliable spark delivery and consistent combustion. The 18.0 hex size and flat seat configuration match the listed BMW applications, including BMW M3, BMW M5, and BMW M6 fitments from the late 1980s and early 1990s.

For shoppers searching for a BMW M3 spark plug, BMW M5 spark plug, or BMW M6 ignition service part, the Denso 5375 provides a direct reference point for the listed vehicles. It is a practical choice when replacing worn plugs on compatible BMW performance engines that call for this specification.

What It Helps Address

• Misfires caused by worn or eroded spark plug electrodes
• Hard starting related to weak ignition output
• Rough idle from inconsistent spark delivery
• Reduced throttle response from degraded plug performance
• Service replacement for specified BMW ignition maintenance

Installation Notes

Verify the thread diameter, reach, seat type, and heat range against the vehicle service specification before installation. Check the pre-gap setting during service and confirm the ignition system is in good condition, including coils, wires, and related secondary ignition components. Use proper torque procedures for the flat-seat design to help prevent thread or sealing damage.

Quality Assurance

Denso manufactures the Iridium Power line with a fine-wire iridium center electrode for precise ignition performance and durable service characteristics. Part number 5375 is built to the listed dimensions and specifications for the confirmed BMW applications.