SKU: 2309 / UPC: 87295123096
NGK Iridium IX Spark Plugs LFR7AIX (Box of 4) for 2009–2024 5.7L & 2015–2024 6.2L HEMI
Optimize ignition performance in your 2009–2024 5.7L VVT or 2015–2024 6.2L HEMI engine with NGK Iridium IX Spark Plugs (LFR7AIX). These premium iridium spark plugs deliver superior spark energy, faster combustion, and improved throttle response compared to standard plugs.
NGK Iridium IX plugs feature an ultra-fine center electrode that’s designed just thick enough to ensure maximum durability and life, yet thin enough to create an accurate and consistent spark. Iridium is significantly stronger than any metal used in spark plugs today 6 times harder than platinum which has allowed NGK engineers to reduce the voltage requirement for a spark. They represent the ultimate evolution of spark plug technology and performance.
Key Features
- Ultra-Fine Iridium Center Electrode – Superior ignitability and long life
- Fine Wire Design – Better spark efficiency and reduced misfires
- High Heat Resistance – Maintains performance under extreme conditions
- Pre-Gapped – Ready to install (recommended gap adjustments below)
- Box of 4 – Complete set for one V8 engine
- NGK Quality – OEM supplier trusted by major manufacturers
Specifications
| Detail | Value |
|---|---|
| Brand | NGK |
| Type | Iridium IX Spark Plug |
| Stock Number | 2309 |
| Part Number | LFR7AIX |
| Thread Diameter | 14 mm |
| Reach | 26.5 mm (1.043 in.) |
| Hex Size | 5/8 inch |
| Gap (Pre-Set) | 0.032 inches |
| Resistor | Yes (5000 ohms) |
| Electrode Core Material | Copper |
| Electrode Tip Material | Iridium |
| Insulator Type | Projected |
| Seat Type | Flat (Gasket) |
| Quantity | Box of 4 |
| Country of Origin | Japan |
| Warranty | NGK Limited Warranty |
Whats Included
- 4 x NGK Iridium IX Spark Plugs (LFR7AIX)
Product Notes
- Designed for 2009–2024 5.7L VVT and 2015–2024 6.2L HEMI V8 engines
- Professional installation and proper gapping recommended
- Replace in complete sets for balanced performance
- Use of nitrous with boost may require even smaller plug gaps.
This Part Fits
| Year Range | Make | Model | Notes |
|---|---|---|---|
| 2009–2024 | Dodge / Chrysler / Jeep / Ram | Models with 5.7L VVT HEMI | Verify exact application |
| 2015–2024 | Dodge / Chrysler / Jeep / Ram | Models with 6.2L HEMI (Hellcat, Demon, etc.) | Verify exact application |
Why Choose NGK Spark Plugs?
- Largest OE spark plug supplier in North America
- Iridium IX plugs offer superior ignitability and longevity
- Precision manufacturing for consistent performance
- Trusted by manufacturers and performance enthusiasts worldwide
Frequently Asked Questions
- Q: Are these good for a stock Hellcat replacement plugs?
- A: Yes. These are a great option for stock and modified Hellcat applications.
- Q: Are these the right ones for 6.1L supercharged?
- A: For boosted applications, NGK 6509 is typically recommended up to 600 RWHP.
- Q: Is this a full set for my HEMI engine?
- A: No. This box of 4 plugs you need to add Quantity of 4 to cart for 16 plugs total for one V8 Hemi engine.
- Q: Is professional installation required?
- A: While experienced DIYers can install them, professional installation ensures proper torque and anti-seize application.
Shipping & Handling
- Method: UPS Ground or FedEx Ground
- Availability: In stock – ships same or next business day
- Packaging: Secure NGK retail packaging





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