NGK IX Iridium Spark Plug 3903
  • Thumbnail  NGK IX Iridium Spark Plug 3903
  • Thumbnail  NGK IX Iridium Spark Plug 3903

NGK IX Iridium Spark Plug 3903




Part #3903
Ground Electrode DesignTapered
Seat StyleGasket
Metal TypeIridium
Gap - Factory Preset1.1 mm = 0.044 in
Electrical Terminal TypeNon-Removable Nut
Reach (in)0.75
Center Electrode DesignFine Wire
Insulator TypeProjected
Short StyleNo
Center Electrode Core MaterialCopper
Thread Size14 mm
Drive Size13/16 in
Ground Electrode ConfigurationSingle
Center Electrode Tip MaterialIridium
Ground Electrode Core MaterialNickel Alloy
Insulator MaterialCeramic
Resistance (Ω)5000
Ground Electrode Tip MaterialNickel
Manufacturer Heat Range Number6


NGK Iridium IX spark plugs are designed specifically for the performance enthusiast. Iridium IX spark plugs offer extreme ignitibility, improved throttle response and superior anti-fouling.

  • checkmarkFine wire Iridium center electrode ensures high durability and a consistently stable spark
  • checkmarkIridium alloy has an extremely high melting point, perfect for today's high-performance engines
  • checkmarkTrivalent metal plating has superior anti-corrosion and anti-seizing properties
  • checkmarkSpecial taper-cut ground electrode shape to allow for more area for flame expansion