NGK ILTR6A-8G 3787 Laser Iridium Spark Plug for Mazdaspeed3 Mazdaspeed6 CX-7

Vehicle Fitment

• 2007-2009 Mazda 3 Mazdaspeed (Mazdaspeed3, 2.3L L4 Turbo)
• 2006-2007 Mazda 6 Mazdaspeed (Mazdaspeed6, 2.3L L4 Turbo)
• 2007-2009 Mazda CX-7 (Base, Grand Touring, Sport, Touring, 2.3L L4 Turbo)
• 2006-2007 Mazda 6 (2.3L L4 Turbo - MZR DISI engine only)

Fitment Notes

• Fits the turbocharged 2.3L MZR DISI (Direct Injection Spark Ignition) engine only; does not fit naturally aspirated 2.3L Mazda applications.
• Mazda 3 fitment applies to the Mazdaspeed3 performance variant only - standard Mazda 3 trims use a different plug.
• Sold individually (1x plug per unit); 4 plugs required per vehicle.
• Pre-gapped at 0.032" (0.8mm) from factory; do not use a standard plier-style gapper - iridium tip damage may occur.

Features

• Laser-welded fine wire iridium tip center electrode delivers precise, consistent spark for improved combustion and throttle response.
• Platinum pad on the ground electrode reduces wear in coil-on-plug distributorless ignition systems for extended service life.
• Iridium alloy construction offers 6x the hardness of platinum and an extremely high melting point - ideal for turbocharged engines.
• Trivalent metal plating on the shell provides superior anti-corrosion and anti-seizing properties for clean, damage-free removal.
• High-grade pure alumina ceramic insulator and 98% pure copper core prevent overheating and support reliable cold starts.
• Tapered seat design eliminates the need for a crush washer, providing a secure, leak-free seal in compatible cylinder heads.
• Built-in 5K Ohm resistor suppresses electromagnetic interference for stable sensor and electronics operation.
• OE-equivalent design engineered to meet Mazda factory service intervals and ignition system specifications.

Specifications

• NGK Part Number: ILTR6A-8G
• NGK Stock Number: 3787
• Plug Type: Laser Iridium (Single Iridium Tip)
• Thread Diameter: 14mm
• Thread Pitch: 1.25mm
• Seat Type: Tapered (No Gasket)
• Thread Reach: 25mm (1")
• Hex Size: 5/8" (16mm)
• Terminal Type: Solid (Non-Removable Nut)
• Pre-Set Gap: 0.032" (0.8mm)
• Resistor: Yes - 5,000 Ohm
• Manufacturer Heat Range: 6
• Center Electrode Material: Iridium Alloy
• Ground Electrode: Platinum Pad
• Torque Spec (Cast Iron Head): 10.8-18 lb-ft
• Torque Spec (Aluminum Head): 7.2-14.5 lb-ft
• OE Service Interval: 75,000 miles

Included Components

• 1x NGK ILTR6A-8G Laser Iridium Spark Plug (pre-gapped at 0.032" / 0.8mm)

Product Description

The NGK ILTR6A-8G (Stock No. 3787) is an OE-grade Laser Iridium spark plug engineered specifically for Mazda's turbocharged 2.3L MZR DISI direct-injection engine found in the Mazdaspeed3, Mazdaspeed6, and CX-7. As the actual OEM or equivalent replacement plug, it matches factory ignition specifications exactly - no modifications or re-gapping required. The laser-welded fine wire iridium center electrode paired with a platinum ground electrode pad delivers superior ignitability, a stable idle, and reduced fouling even under the elevated cylinder pressures and temperatures of a turbocharged application.

Installation is straightforward thanks to the tapered seat design, which threads directly into the cylinder head without a crush washer. The 5K Ohm built-in resistor protects the vehicle's sensitive direct-injection electronics from spark-generated interference. With a 75,000-mile OE-recommended service interval, these plugs provide long-lasting reliability well beyond standard copper alternatives. NGK is the OEM ignition supplier for Mazda, making this plug the definitive choice for maintaining factory performance on the Mazdaspeed platform.