DENSO 4116 U-Groove Standard Spark Plug

The DENSO 4116 (X27ESR-U) U-Groove Standard Spark Plug delivers superior ignition performance through advanced engineering and precision manufacturing. Built to OE standards, this spark plug utilizes DENSO's innovative U-Groove ground electrode design to optimize combustion efficiency and engine performance.

Key Features:

• U-Groove ground electrode creates a larger spark nucleus and flame front for more complete combustion
• Improves fuel efficiency and throttle response compared to conventional spark plugs
• Machine-rolled threads prevent seizing or cross-threading during installation and removal
• 100% pre-fired to ensure reliable operation and consistent performance
• Purified alumina powder insulator provides exceptional strength and thermal conductivity
• Five-rib insulator design reduces flashover and minimizes voltage loss
• Dual copper and glass seal creates a gas-tight bond between center electrode and insulator
• Fires leaner fuel mixtures more effectively than standard plugs
• Lasts twice as long as conventional spark plugs

The unique channeled ground electrode design allows the flame to grow within the groove, resulting in less flame dissipation and improved combustion consistency. This translates to better emission control, enhanced fuel economy, and more responsive acceleration. Manufactured to strict OE specifications with quality materials throughout.

Installation Torque: 11-18 lb-ft (cast iron or aluminum heads)