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Iridium IX
Designed specifically for the performance enthusiast. Iridium IX® offers extreme ignitability, improved throttle response and superior anti fouling
  • Fine Iridium tip ensures high durability and a consistently stable spark
  • Iridium alloy has extremely high melting point, perfect for today’s high-tech, high-performance engines
  • Trivalent Metal Plating - superior anti-corrosion and anti-seizing properties
  • Tapered ground electrode minimizes quenching
  • Outstanding acceleration, high fuel efficiency and durability
  • Ultimate design, technology and performance.

Spark Plug Type Performance Differences

Correct Way to Check, Set, and Adjust Your Spark Plug Gap

Technical Bulletin for 5.4L 2004-2005 Ford F-150, Expedition, Super Duty & Lincoln Navigator
Center Electrode Core MaterialCopper Core
Center Electrode Tip MaterialIridium
Gap Size0.04 in
Ground Electrode Quantity1
Hex Size5/8"
Insulator HeightISO
Manufacturer Heat Range6
Additional Info5K Ohm
Seat TypeTapered
Thread Diameter14 MM
Ground Electrode Tip DesignTaper Cut
Ground ConfigurationStandard
Ground Electrode Core MaterialNickel Core
Alternate/OEM Part Number(s): TR6IX

NGK Warranty Information:
Spark Plug Wires: Limited Lifetime; Ignition Coils: 3 Years / 36,000 Miles; All Other Parts: 60 Days