NGK IZFR6K-11S 5266 Laser Iridium Spark Plug 2006-2011 Honda Civic 1.8L R18

Vehicle Fitment

• 2006-2011 Honda Civic DX (1.8L I4 R18A1, FWD)
• 2006-2011 Honda Civic LX (1.8L I4 R18A1, FWD)
• 2009-2011 Honda Civic LX-S (1.8L I4 R18A1, FWD)
• 2006-2011 Honda Civic EX (1.8L I4 R18A1, FWD)
• 2009-2011 Honda Civic EX-L (1.8L I4 R18A1, FWD)
• 2006-2011 Honda Civic Hybrid (1.3L I4 IMA, FWD)
• 2011 Honda Civic Hybrid-L (1.3L I4 IMA, FWD)
• 2006-2011 Honda Civic Si (2.0L I4 K20Z3, FWD)
• 2008 Honda Civic MUGEN Si (2.0L I4 K20Z3, FWD)
• 2006-2011 Honda Civic GX (1.8L I4 R18A, Natural Gas, FWD)

Fitment Notes

• This is the Honda OEM NGK spark plug for the 8th-generation Civic platform (2006-2011), replacing Honda OEM part numbers 9807B-561BW and 9807B561BWA0.
• Fitment covers multiple engine variants on the 8th-gen Civic - confirm your engine code (R18A1 for 1.8L, K20Z3 for Si, IMA for Hybrid) before ordering.
• Honda GX (natural gas) variant compatibility is noted in the NGK fitment list; however, Honda OEM documentation specifies this plug applies to 1.8L automatic transmission applications - verify your specific GX configuration before installation.
• Pre-gapped at 0.044" (1.1mm) from factory; always verify gap before installation.
• Sold individually (1x plug per unit); 4 plugs required per vehicle.

Features

• Laser-welded iridium fine wire center electrode delivers a precise, stable spark with reduced voltage requirements for improved combustion efficiency.
• Trapezoid-shaped platinum ground electrode pad provides slow, even wear in coil-on-plug (COP) ignition systems for extended service life.
• Projected tip design promotes more efficient flame kernel development within the cylinder for improved throttle response and fuel economy.
• Trivalent metal shell plating delivers superior anti-corrosion and anti-seizing properties for clean removal from Honda's aluminum cylinder heads.
• High-grade pure alumina ceramic insulator and 98% pure copper core prevent overheating and maintain stable electrode temperatures.
• Built-in 5K Ohm resistor suppresses EMI/RFI interference to protect Honda's engine management and VTEC electronics.
• Triple gasket seal prevents combustion gas leakage for long-term reliability at factory service intervals.
• OE-equivalent design - the actual Honda factory plug for the R18A1-equipped 8th-gen Civic platform.

Specifications

• NGK Part Number: IZFR6K-11S
• NGK Stock Number: 5266
• Plug Type: Laser Iridium (Single Iridium Tip / Platinum Ground)
• Thread Diameter: 14mm
• Thread Pitch: 1.25mm
• Seat Type: Flat (Gasket)
• Thread Reach: 19mm (3/4")
• Hex Size: 5/8" (16mm)
• Terminal Type: Solid (Non-Removable Nut)
• Pre-Set Gap: 0.044" (1.1mm)
• Center Electrode Material: Iridium Fine Wire
• Center Electrode Tip: Projected
• Ground Electrode: Trapezoid Nickel Core / Platinum Pad
• Resistor: Yes - 5,000 Ohm
• Manufacturer Heat Range: 6
• Torque Spec (Cast Iron): 18-25.3 lb-ft
• Torque Spec (Aluminum): 18-21.6 lb-ft
• Honda OEM Replacement For: 9807B-561BW / 9807B561BWA0

Included Components

• 1x NGK IZFR6K-11S Laser Iridium Spark Plug (pre-gapped at 0.044" / 1.1mm)

Product Description

The NGK IZFR6K-11S (Stock No. 5266) is the OEM-specified Laser Iridium spark plug for the 8th-generation Honda Civic (2006-2011), covering all trims equipped with the 1.8L R18A1, 2.0L K20Z3 Si, and 1.3L IMA Hybrid engines. As the actual Honda factory plug - replacing Honda OEM part 9807B-561BW - it installs as a direct drop-in with no gap adjustment required under stock conditions. The laser-welded iridium center electrode paired with a trapezoid platinum ground pad delivers consistently stable spark energy across the full operating range, maintaining Honda's recommended long-life service interval of up to 100,000 miles.

The projected tip design and 0.044" pre-set gap are engineered specifically for the combustion chamber geometry of Honda's R18 and K20 engines, promoting efficient flame kernel development and clean burn without over-stressing the ignition coil. The 5K Ohm resistor protects Honda's COP ignition system and VTEC electronics from spark-generated interference. Sold individually - four plugs are required per vehicle, and Honda recommends replacing all plugs as a set to ensure balanced cylinder-to-cylinder performance.