NGK 7913 SILFR6A Laser Iridium Spark Plug for Hellcat/Subaru

Vehicle Fitment

• 2015-2023 Dodge Challenger, 6.2L supercharged V8 (Hellcat)
• 2015-2023 Dodge Charger, 6.2L supercharged V8 (Hellcat)
• 2021-2023 Dodge Durango, 6.2L supercharged V8 (SRT Hellcat)
• 2018-2021 Jeep Grand Cherokee, 6.2L supercharged V8 (Trackhawk)
• 2021-2023 Ram 1500, 6.2L supercharged V8 (TRX)
• 2005-2009 Subaru Legacy
• 2005-2009 Subaru Outback (confirmed including 2.5i, 2.5i Limited, and R L.L. Bean Edition trims)
• 2008-2009 Subaru Tribeca
• 2008-2014 Subaru Impreza
• 2009-2013 Subaru Forester
• Subaru WRX STI (confirm exact model years for your application)

Fitment Notes

• OE cross-reference: Subaru 22401AA670
• Aftermarket cross-reference: Denso IKH20TT, PKH20TT, 4704, 4506
• Sold individually - the 6.2L supercharged V8 requires 8 plugs; Subaru boxer engines typically require 4

Features

• Iridium alloy center electrode is six times harder than platinum for exceptional durability
• Square platinum electrode (SPE) design on the ground electrode provides the best ignitability and service life for high-heat engines
• 98% pure copper core offers superior heat dissipation, conductivity, and ultra-wide heat range capability
• Fine-wire platinum tipped ground electrode ensures a slow wear rate, stable idle, and superior anti-fouling
• Trivalent metal plating provides strong anti-corrosion and anti-seizing protection
• Engineered as an OE or equivalent high-ignitability design for demanding, high-output applications

Specifications

• NGK stock number: 7913
• Service/OE number: SILFR6A
• Center electrode material: Copper core, iridium tip
• Ground electrode: Square platinum electrode (SPE), nickel core
• Pre-gap: 0.032 in.
• Seat type: Flat
• Terminal type: Non-removable nut
• Torque spec: 18-25.3 lb-ft (cast iron), 18-21.6 lb-ft (aluminum)

Included Components

• 1x Spark Plug

Product Description

The NGK 7913 (SILFR6A) is a Laser Iridium High Ignitability spark plug engineered for two very different but equally demanding applications: Stellantis's supercharged 6.2L HEMI V8 (used in the Hellcat, Trackhawk, and TRX performance models) and a range of Subaru boxer engines across the Legacy, Outback, Impreza, Forester, Tribeca, and WRX STI. Its iridium center electrode is six times harder than platinum, built to withstand the heat and cylinder pressure of a supercharged engine as well as the high-RPM demands of Subaru's boxer layout.

The square platinum electrode (SPE) ground design is engineered specifically for high ignitability and long service life in high-heat conditions, while the 98% pure copper core supports strong heat dissipation and a wide usable heat range. Trivalent metal plating protects against corrosion and seizing in the cylinder head, which matters on both a boosted V8 and a boxer engine known for tight plug access.

This is a strong OE-quality replacement whether you're servicing a supercharged Hellcat/Trackhawk/TRX or a Subaru boxer engine. Since plug count and access vary significantly between these platforms - 8 plugs for the supercharged V8, 4 for most Subaru boxer engines - confirm the correct quantity for your vehicle, and note that boxer engine plug access is notoriously tight, so budgeting extra time for a Subaru installation is worthwhile.