Why NGK Iridium?
More Durability and a Higher Melting Point compared to Platinum, better center electrode anti-oxidation and anti-erosion, improved ignition, superior anti-fouling, lower required voltage, new metal shell plating process for better anti-corrosion. One Step Colder plugs are recommended for cars with heavy modifications. These Iridium Spark Plugs will get your Turbo Subaru running smoother and free up some power through increased efficiency and increased heat resistance. These are available in stock heat or one step colder for cars running approximately 100 horsepower more than stock.
Please Note:
1. Iridium plugs are able to use a larger gap setting with less voltage. Some customers choose to re-gap these plugs to correct misfiring or tune for optimal spark — do so at your own risk — slide-type plug gapper will damage the fragile iridium tip.
Heat Range:
– Stock Heat Range for 2019-2021 STi
- Thread Diameter – 14mm
- Thread Pitch – 1.25mm
- Seat Type – Gasket
- Reach – 26.5mm (1.04″)
- Hex Size – 5/8″ (16mm)
- Terminal Type – Solid
- Overall Height – ISO
- Gap – .024″ (0.6mm)
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