Denso 4010 Spark Plug

Denso 4010 U-Groove Spark Plug

Denso 4010 is a conventional spark plug built around a U-groove ground electrode to improve ignitability and support more efficient combustion. It uses a copper center electrode core with nickel tip materials and a 5000-ohm resistor for stable secondary ignition performance.

For drivers searching for a Denso spark plug for Honda Civic, Toyota Corolla, or other import applications, this U-Groove Conventional design delivers a straightforward OE-style service part with the dimensions and heat range needed for proper engine operation. The Denso 4010 is also referenced under DENSO Auto Parts U24FSR-U.

Key Features

• U-groove ground electrode design for improved spark exposure
• Conventional spark plug construction for routine ignition service
• 5000-ohm resistor for controlled electrical resistance
• Copper center electrode core for dependable heat transfer
• Nickel center and ground electrode tip materials
• 14.00 mm thread diameter, 12.70 mm reach, and flat seat type
• 0.7 pre-gap size with a 16.0 mm hex size
• Manufacturer heat range 24

Product Details

The Denso U-Groove Conventional line focuses on improving ignitability through electrode geometry rather than exotic materials. On the Denso 4010, the U-shaped ground electrode helps expose the spark kernel more effectively, which supports cleaner combustion and consistent engine response in the right application. This spark plug is a practical choice for import vehicle maintenance where OE-style dimensions and a conventional plug design are required.

Search terms such as Denso 4010 spark plug, U24FSR-U replacement, and Denso spark plug for Honda Civic or Toyota Corolla are commonly used by buyers looking for this exact secondary ignition part.

What It Helps Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from weak or inconsistent ignition output
• Misfire conditions related to degraded plug electrodes
• Reduced fuel efficiency from incomplete combustion
• Loss of throttle response from aging secondary ignition components

Installation Notes and Tips

Verify thread diameter, reach, seat type, and heat range before installation. The Denso 4010 uses a 14.00 mm thread, 12.70 mm reach, and flat seat configuration, so it should be matched to the engine specification exactly. Check the pre-gap against the vehicle service information before installing, and inspect ignition wires or coils at the same time if the old plug shows signs of fouling or wear.

Compatible With applications should be confirmed by engine specification and service data for the exact vehicle. For fitment-based searches, use the vehicle year, make, and model listed by the catalog before ordering a Denso spark plug for Honda Civic, Toyota Corolla, or similar import maintenance needs.

Quality Assurance

Denso is known for OE-level ignition component engineering, and the U-Groove Conventional series is built to meet the dimensional and performance requirements of the specified application. Part number 4010 is manufactured as a conventional replacement spark plug for secondary ignition service.