SKU: 50003-MR45XLZ | UPC: 4957266720509
HKS SUPER FIRE RACING MR45XLZ Spark Plugs for 2005-2021 Subaru STI Forester XT Legacy GT Outback XT
HKS SUPER FIRE RACING MR45XLZ spark plugs feature iridium construction for turbocharged Subaru EJ25 engines. These plugs fit 2005-2021 Subaru WRX STI Forester XT Legacy GT and Outback XT models. Stronger spark improves combustion for more horsepower torque and throttle response under boost.
Key Features
- 0.8mm Pure Iridium Center Electrode: Delivers stable spark in high rev high boost conditions for consistent power output
- 0.8mm Platinum Ground Electrode: Resists erosion and maintains gap for long service life in racing use
- Projected Insulator Design: Accelerates flame growth to reduce misfires and increase efficiency
- Heat Range 45: Controls temperature in turbo applications to avoid preignition or fouling
- M12 x 35mm Thread Reach: Exact match for Subaru EJ cylinder heads with 16mm hex size
Product Notes
- Sold individually as direct OEM replacement
- Pre-gapped to 0.8mm verify gap before installation
- Small lightweight package for fast shipping
Installation Notes
- Professional installation recommended.
- Torque to 25 Nm or 18 ft-lbs using 16mm thin wall socket
- Apply anti-seize compound to threads compatible with OEM coils
This Part Fits
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2005-2009 | Subaru | Legacy | GT |
| 2005-2009 | Subaru | Outback | XT |
| 2009-2013 | Subaru | Forester | XT |
| 2008-2014 | Subaru | Impreza WRX | STI |
| 2015-2021 | Subaru | WRX STI | – |
Why Choose HKS?
- Leader in JDM tuning since 1973 with motorsport heritage
- Engineered tested for boosted Subaru applications
- Made in Japan with precision tolerances
Frequently Asked Questions
- Q: Does MR45XLZ fit 2015-2021 Subaru WRX STI?
A: Yes direct replacement for EJ257 turbo engines in 2015-2021 WRX STI models - Q: What materials are used in electrodes?
A: 0.8mm pure iridium center electrode paired with 0.8mm platinum ground electrode for durability - Q: What is the service interval?
A: Up to 40000 miles in street use replace sooner in track or high boost setups
Shipping & Handling
- Method: UPS Ground or USPS Priority
- Availability: In stock – ships same or next business day
- Packaging: Original HKS box dimensions 4in x 3in x 2in
- Weight: 0.15 lbs
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