The GI3-5 Industrial Ultimate Durability Double Iridium Saver-DDI spark plug reduces maintenance costs by extending work life in high compression lean burn engines. This unique design guarantees high reliability for withstanding high combustion pressure by incorporating a stress resistant monolithic resistor that adheres to the resistor glass in the high temperature furnace.

Specific details of this model include:

  • Thread Size: 18mm x 1.5
  • Reach: 20.6mm (13/16″)
  • Hex Size: 22.2mm (7/8″)
  • Gap: 0.3mm (.012″)
  • 100% Pre-Fired: All Denso spark plugs are 100% pre-fired to assure the highest quality possible.
  • Copper-Glass Seal: Bonds the center electrode and insulator together for a gas-tight seal. Maintains proper heat and excludes hot combustion gases.
  • Purified Alumina Powder Insulator: Provides exceptional dielectric strength and thermal conductivity allowing the material to stand up to extreme stress.
  • Solid terminal nut.
  • Platinum-alloy tipped fine wire ground electrode, with an Iridium pad on the ground electrode and an Iridium pad without cross grooves on the center electrode.

The Denso GI3-5 Industrial Ultimate Durability Double Iridium Saver-DDI works in the following engine applications:

CATERPILLAR: G3500 (non B, C and E series), G3600 series

CUMMINS: Q19G, QSV81-V16, QSV91-V18

GUASCOR: FG180, FGLD180, FG240, FGLD240, FGLD360, FGLD480

GE JENBACHER: J612, J616, J620 (1995/9 – BMEP = 16 bar or less)

PERKINS: 4000 Series

SUPERIOR: 1706G2, 1712G1


AT Series: 8L-AT25GL / AT27GL (13/16″ Reach Heads), 12V-AT25GL / AT27GL (13/16″ Reach Heads)
VGF Series Inline 6: F18G, F18GL/GLD
VGF Series Inline 8: H24G, H24GL/GLD
VGF Series V-12: L36GL/GLD
VGF Series V-16: P48GL/GLD
VHP Series Inline 6: 2895GL (13/16″ Reach Heads), 3521GL (13/16″ Reach Heads)
VHP Series V-12: L5108GL (13/16″ Reach Heads), L5790GL (13/16″ Reach Heads), L7042GL (13/16″ Reach Heads)
VHP Series V-16: P5115GL, P9390GL (13/16″ Reach Heads)