NGK Iridium Spark Plugs IFR6T11 (4589) 4-Pack — Fine‑Wire Iridium, OEM Fit for Toyota & Lexus

NGK 4589 (IFR6T11) Laser Iridium spark plugs are high‑performance, OE‑grade iridium plugs sold in a 4-pack and engineered to deliver consistent ignition and long service life for specified Toyota, Lexus, Mazda, Pontiac, Scion, Lotus and Daewoo engines.

These IFR6T11 spark plugs combine a fine‑wire iridium center electrode with a platinum ground pad and a copper core to balance ignition reliability, heat control and wear resistance. Manufactured to OEM tolerances and supplied by NGK — a leading original equipment spark plug maker — they are intended for engines listed in the compatibility section and match OE reach, thread and heat range specifications for those applications.

Which vehicles and engines will accept the NGK 4589 IFR6T11 plugs?

The IFR6T11 (stock number 4589) fits a variety of late‑20th and early‑21st century models across several brands. Always cross‑check the part number with your vehicle’s manual or NGK to confirm fitment before purchase.

• Toyota: Camry, Celica, Corolla, Highlander, Matrix, MR2, Previa, RAV4, Solara (various 1.8L–2.4L years listed).
• Lexus: HS250h 2.4L (2010–2012); Mazda: Miata 1.6L (1990–1993).
• Scion and Pontiac: tC, xB, Vibe 1.8L/2.4L model years noted; plus Lotus Elan and Daewoo Lanos specific years.

How do these iridium plugs improve ignition and longevity?

Iridium on the center electrode provides a very hard, wear‑resistant tip that supports a stable spark over many more miles than standard electrodes. The copper core and high‑grade ceramic insulator help dissipate heat and minimize misfires under normal operating conditions.

• Fine‑wire iridium center electrode for precise spark and extended life.
• Platinum pad on the ground electrode to ensure even wear.
• 98% pure copper core and alumina ceramic insulator for heat control and reliable starts.

What are the key technical specs and installation points to know?

These plugs are manufactured with a 0.750 in reach, a 14.0 mm thread diameter, a 5/8" (16 mm) hex and a pre‑gap of 0.044 in (1.1 mm). They include a crush washer and a non‑removable nut terminal; the resistor value is specified for OEM‑style ignition systems.

• Reach: 0.750 in (19.0 mm); thread diameter: 14.0 mm; hex size: 5/8" (16 mm).
• Pre‑gap: 0.044 in (1.1 mm); insulator height: 50.5 mm; seat type: flat.
• Center electrode tip: iridium with copper core; ground electrode tip: platinum; resistor included.

Will these plugs require special tools or adjustments for installation?

Installation follows typical spark plug replacement procedures for OEM‑style plugs and requires correct torque and gap verification. Use a torque wrench set to your vehicle manufacturer’s specification and recheck the gap if a plug is overtightened or if heavy deposits are present.

• No special ignition tools required; use a 5/8" (16 mm) socket and appropriate torque wrench.
• Verify the 0.044 in (1.1 mm) pre‑gap if you adjust for specific engine setups.
• Always consult the vehicle manual for torque and sequence to avoid thread damage.

Who is this for? Drivers and mechanics seeking OEM‑quality replacement plugs for the listed Toyota, Lexus, Mazda, Pontiac, Scion, Lotus and Daewoo engines who want longer service life and a precise spark from a trusted manufacturer. Ideal for owners who prefer a direct OE‑spec iridium upgrade to maintain factory performance and reduce re‑service frequency.

Note: This listing contains four IFR6T11 NGK Laser Iridium spark plugs (stock number 4589). Confirm part compatibility with your vehicle’s documentation or NGK before ordering.