NGK Laser Iridium Spark Plug Box of 4 (LZFR5CI-11) - 92145

The NGK Laser Iridium Spark Plug LZFR5CI-11 (part number 92145) is a premium NGK iridium spark plug sold in a convenient box of 4, purpose-built for the high-compression demands of modern performance and everyday engines alike. Engineered with a fine-wire iridium center electrode and a platinum ground electrode, this NGK laser iridium spark plug delivers a consistently stable spark and long service life — making it a top-tier choice for Chrysler, Dodge, Fiat, Jeep, and Ram vehicles equipped with the 5.7L HEMI V8 and other compatible engines. If you're replacing spark plugs on a Ram 1500, Dodge Challenger, Charger, Durango, Jeep Grand Cherokee, or Chrysler 300 with the 5.7L V8, this is the recommended iridium-grade plug for that application.

Key Features & Benefits

• Fine-wire iridium center electrode (0.6mm): The laser-welded iridium tip provides high durability and a consistently stable spark, reducing misfire and supporting efficient combustion across the RPM range.
• Iridium alloy with an extremely high melting point: Iridium's material properties make it well-suited for today's high-tech, high-performance engines that run hotter and under greater stress than ever before.
• Platinum ground electrode: Pairs with the iridium center electrode to balance wear and extend the plug's overall service life beyond what a standard copper plug offers.
• Trivalent metal plating: Provides superior anti-corrosion and anti-seizing properties, making future removal easier — particularly important on aluminum cylinder heads.
• Pure alumina silicate ceramic insulator: Delivers superior strength and better heat transfer, helping the plug maintain proper operating temperature and resist cracking under thermal stress.
• 98% pure copper core: Aids in efficient heat removal from the firing tip, helping to prevent pre-ignition and overheating.
• Corrugated ribs on the insulator: Prevent flashover, protecting ignition performance even in high-voltage ignition systems.
• Triple seals: Prevent combustion gas leakage past the plug body for reliable sealing over the long service interval.
• Extended projection tip: The center electrode features extended projection geometry, which can improve ignitability and flame kernel development.
• 5k Ohm resistor: Suppresses radio frequency interference (RFI) to protect sensitive onboard electronics and infotainment systems.
• Up to 100,000-mile longevity rating: NGK rates this plug for long-life service, reducing how often you need to schedule a plug change interval.

Specifications

• Part Number (MPN): 92145
• Plug Code: LZFR5CI-11
• Brand: NGK
• Quantity per Box: 4
• Thread Diameter: 14mm
• Thread Pitch: 1.25mm
• Seat Type: Gasket
• Reach: 26.5mm (1.04")
• Hex Size: 5/8" (16mm)
• Terminal Type: Solid
• Gap: 0.043" (1.1mm)
• Center Electrode Material: Iridium — Fine Wire, 0.6mm
• Center Electrode Projection: Extended Projection
• Ground Electrode Material: Platinum — Standard Type
• Heat Range: 5
• Resistor: Yes — 5k Ohm
• Insulator: Pure alumina silicate ceramic
• Torque (Cast Iron Head): 18–25.3 lb-ft
• Torque (Aluminum Head): 18–21.6 lb-ft
• Longevity Rating: Up to 100,000 miles
• Warranty: 60 days

Fitment

The NGK 92145 LZFR5CI-11 is a direct-fit replacement plug compatible with a wide range of Chrysler, Dodge, Fiat, Jeep, and Ram vehicles. Per sourced fitment data, the 5.7L HEMI V8 requires 16 plugs total (the engine has two plugs per cylinder), so you will need four boxes of four for a complete engine service on HEMI-equipped trucks and SUVs.

Confirmed compatible vehicle families include:

• Ram 1500 & 1500 Classic with 5.7L V8 HEMI — 2009–2023 (and select 2024 trims)
• Dodge Durango with 5.7L V8 — 2008–2024 (GT, R/T, SRT, Citadel, Pursuit, and more)
• Dodge Challenger with 5.7L V8 — 2008–2024
• Dodge Charger with 5.7L V8 — 2008–2024
• Chrysler 300 with 5.7L V8 — 2008–2023
• Jeep Grand Cherokee & Grand Cherokee L with 5.7L V8 — 2008–2024
• Jeep Wagoneer with 5.7L V8 — compatible trims per NGK data
• Fiat compatible applications — 2016–2018
• Ram (broader lineup) — 2011–2024

Always verify fitment by your exact year, make, model, and engine before ordering. Use ThreePiece.us's fitment tool or contact our team if you need confirmation. Note: because the 5.7L HEMI uses a dual-plug-per-cylinder design, a full tune-up requires 4 boxes (16 plugs).

What's in the Box

• 4x NGK LZFR5CI-11 Laser Iridium Spark Plugs (pre-gapped at 0.043" / 1.1mm from the factory)
• Original NGK packaging

Why Buy from ThreePiece.us

At ThreePiece.us, we make it straightforward to get the right NGK spark plugs for your vehicle without the guesswork. Here's what you get when you order with us:

• Free shipping on every order — no minimum, no surprises at checkout.
• Affirm financing available — split your purchase into manageable payments, especially useful when you're buying multiple boxes for a full HEMI tune-up.
• Expert fitment support — not sure how many boxes you need, or want to confirm this plug fits your specific trim? Our team is here to help you get it right the first time.
• Genuine NGK parts — you're getting the actual NGK 92145 with the original packaging and factory-set gap, not a generic substitute.

Frequently Asked Questions

Q: How many NGK 92145 spark plugs does my 5.7L HEMI need for a full tune-up?
A: The 5.7L HEMI V8 uses two spark plugs per cylinder across its 8 cylinders, meaning you need 16 plugs total for a complete service. Since this listing is a box of 4, you'll need to order 4 boxes to do the full engine.

Q: Are these plugs pre-gapped from the factory?
A: Yes. The NGK LZFR5CI-11 comes factory-set at a gap of 0.043" (1.1mm). Because iridium and platinum fine-wire electrodes can be damaged by regapping tools, NGK generally recommends installing these plugs at the factory gap without adjustment.

Q: What is the correct torque spec for installing the NGK 92145?
A: NGK specifies 18–25.3 lb-ft for cast iron cylinder heads and 18–21.6 lb-ft for aluminum cylinder heads. Most 5.7L HEMI applications use aluminum heads, so refer to your vehicle's service manual and use a calibrated torque wrench for proper installation.

Q: Does the NGK 92145 fit the Ram 1500 TRX or Durango SRT Hellcat?
A: The Ram 1500 TRX is listed in NGK's fitment data for the 92145. However, the Durango SRT Hellcat uses a supercharged 6.2L engine, which is a different application — verify fitment for Hellcat models using ThreePiece.us's fitment tool or contact our team before ordering.