DENSO 5303 Iridium Power Spark Plug - IK16

The DENSO 5303 (IK16) Iridium Power Spark Plug is a high-performance ignition component engineered with the world's smallest 0.4mm iridium-tipped fine wire center electrode. This ultra-fine electrode reduces the voltage required to fire the plug, delivering a stronger, more precise spark for improved combustion efficiency and throttle response.

Key Features:

• 0.4mm iridium-tipped center electrode — reduces required firing voltage and improves ignition performance
• Patented 360-degree laser welding — bonds the iridium tip to the electrode for maximum durability and precision
• Tapered U-Groove ground electrode — increases ignitability, minimizes quenching effect, and promotes even flame propagation
• Purified alumina powder insulator — delivers exceptional strength and thermal conductivity
• Five-rib insulator design — prevents flashover under high-voltage conditions
• Copper-glass seal — bonds center electrode and insulator for a gas-tight seal
• Machine-rolled threads — prevent seizing or cross-threading during installation and removal
• 100% pre-fired at the factory — ensures highest quality out of the box
• Burnished nickel plating — provides high-temperature endurance and corrosion resistance

Specifications:

• Plug Number: IK16
• Thread Size: M14
• Thread Reach: 19mm
• Seat Type: Gasket
• Hex Size: 16mm
• Preset Gap: 1.1mm
• Heat Range: 16
• Resistor Value: 5,000 Ohms
• Center Electrode Material: Iridium-tipped, Copper Core
• Torque Spec — Cast Iron: 26–30 lb-ft | Aluminum: 15–22 lb-ft

The DENSO IK16 Iridium Power spark plug withstands temperatures exceeding 4,000°F and requires up to 5,000 fewer volts to fire compared to conventional spark plugs. Sold individually.