Denso 4116 Spark Plug

Denso 4116 Spark Plug for Ferrari and Lamborghini

The Denso 4116 is a conventional spark plug built for precise ignition performance in high-performance engines. Its U-Groove ground electrode design helps improve ignitability, while the copper core and nickel electrode materials support consistent spark delivery and engine efficiency.

Key Features

• U-Groove ground electrode tip design for improved ignitability
• Conventional spark plug construction for secondary ignition systems
• 5000 ohm resistance for controlled electrical performance
• Copper center electrode core with nickel center electrode tip
• Nickel ground electrode core material with standard ground configuration
• 0.7 pre-gap size, 12.00 mm thread diameter, 19.00 mm reach, and 18.0 mm hex size
• Flat seat type and Manufacturer Heat Range 27

Detailed Description

Built under Denso’s U-Groove Conventional line, the 4116 spark plug is engineered for drivers who need dependable ignition characteristics in demanding performance applications. The U-Groove design increases the exposed spark area at the ground electrode, which supports more efficient ignition and stable combustion. This part number 4116 is also referenced as Denso Auto Parts X27ESR-U for the same application.

Compatible With Ferrari 348 TS, Ferrari 348 GTS, Ferrari Mondial 3.2, Ferrari Mondial t, Ferrari Testarossa, and Lamborghini Diablo applications across the listed model years. The Denso 4116 is a direct-fit style spark plug for vehicles that call for the specified thread diameter, reach, seat type, and heat range.

What This Spark Plug Helps Address

• Hard starting caused by worn or inconsistent spark plugs
• Misfire conditions related to weak ignition output
• Rough idle from degraded spark quality
• Incomplete combustion that can reduce engine smoothness
• Loss of throttle response from aging secondary ignition components

Installation Notes and Tips

Verify the required thread diameter, reach, seat type, heat range, and pre-gap before installation. Use the vehicle service specification for final gap verification and torque, and inspect the ignition system for wear before replacing plugs. This part is listed for 1991-1999 Lamborghini Diablo, 1993-1994 Ferrari 348 GTS, 1989-1993 Ferrari Mondial t, 1989-1992 Ferrari 348 TS, 1985-1991 Ferrari Testarossa, and 1986-1988 Ferrari Mondial 3.2.

Quality Assurance

Denso manufactures ignition components to OE-level specifications for precise fit and consistent performance characteristics. The 4116 spark plug is built with defined electrical resistance, electrode materials, and heat range to support reliable service in the listed Ferrari and Lamborghini applications.