Denso 4045 Spark Plug

Denso 4045 U-Groove Spark Plug Overview

The Denso 4045 is a conventional spark plug built for steady ignition performance in secondary ignition systems. Its U-groove ground electrode design helps improve ignitability, supporting more efficient combustion in the right engine application. This spark plug is a practical choice for drivers searching for a Denso spark plug 4045 replacement with OE-style construction.

Key Features

• U-groove ground electrode tip design for improved spark exposure
• Nickel ground electrode tip material and nickel center electrode tip material
• Copper center electrode core for reliable conductivity
• 5000 ohm resistor for radio noise suppression
• Standard ground configuration with a flat seat
• 14.00 mm thread diameter, 19.00 mm reach, and 20.6 mm hex size
• Pre-gapped to 0.8 mm
• Manufacturer heat range 27

Product Details

Built under Denso’s U-Groove Conventional line, this spark plug focuses on consistent ignition and dependable fitment characteristics for engines that call for this specification. The U-shaped ground electrode helps expose the spark kernel more effectively than a standard ground design, which can support cleaner combustion and smoother operation in the correct application. If you are comparing Denso 4045 ignition parts or looking for a Denso W27ESR-U cross-reference, this plug matches that application family.

Compatible With select Honda Civic and Toyota Corolla applications where the specified thread diameter, reach, seat type, and heat range match the engine requirements. For buyers searching long-tail terms such as Denso 4045 spark plug for Honda Civic or Denso 4045 spark plug for Toyota Corolla, verify engine code and OE specifications before installation.

This part cross-references DENSO Auto Parts (e.g., W27ESR-U) for the same application.

What It Helps Address

• Hard starting caused by worn or inefficient spark plugs
• Misfire concerns related to weak ignition output
• Rough idle from inconsistent spark delivery
• Reduced combustion efficiency in the specified engine application
• Radio-frequency interference in ignition systems that require resistance

Installation Notes

Confirm the engine’s required thread diameter, reach, seat type, heat range, and pre-gap before installation. Use the correct torque specification for the cylinder head material and inspect ignition wires or coils for wear at the same time. For Honda Civic and Toyota Corolla service work, match the plug to the exact engine configuration rather than the vehicle name alone.

Quality Assurance

Denso’s U-Groove Conventional spark plug line is built around OE-style ignition specifications and consistent electrode construction. The Denso 4045 is manufactured to the listed electrical and dimensional requirements for the intended application.