IK20TT — Denso Iridium TT Twin Tip Spark Plug

Part Number

Denso IK20TT (Denso part 4702). Iridium TT series. [Verified — Denso, Amazon, multiple retailers confirm 3UZ-FE fitment]

What It Is

Spark plug for the 3UZ-FE 4.3L V8. Twin-tip design: 0.4mm iridium centre electrode + 0.7mm platinum ground electrode. V8 requires 8 plugs.

Specifications

  • Gap: 0.040”
  • Thread: 14mm
  • Reach: 17.5mm
  • Hex: 16mm
  • Lifespan: 60,000-100,000 km (iridium)

Fitment

SC430 (UZZ40) 2001-2010 with 3UZ-FE. Also fits LS430, GS430, LX470 (2UZ-FE). [Verified]

Where to Buy (Australia)

  • Automotive Superstore — A134 total.
  • eBay AU — search “Denso IK20TT” or “Denso 4702”
  • Amazon

Service Notes

  • At 153,081 km (Leif’s car, April 2026), plugs may never have been changed — likely overdue
  • No need to stockpile — IK20TT fits dozens of Toyota/Lexus models and will remain available for years
  • Integrated crush washer — no separate gasket/seal needed
  • Torque: 18-21 Nm (13-15 ft-lbs) — do not over-tighten, iridium ceramic is fragile
  • IK20TT is an upgrade over factory SK20R11 (twin tip vs single tip) from the same OEM supplier