PRODUCT DETAILS
NGK Laser Iridium Spark Plugs for 06-11 Civic 1.8 (Set of 4)
Your 2006-2011 Civic 1.8 runs four plugs, and when they wear out the idle gets lumpy and cold starts take an extra crank. This is a set of four NGK 5266 Laser Iridium spark plugs (IZFR6K-11S), the factory plug for the R18. One box does the whole engine.
What It Is and Why It Works
IZFR6K-11S is what Honda screwed into the R18A1 at the factory, boxed under Honda part 9807B-561BW. NGK builds it with a 0.6 mm fine-wire iridium center and a platinum pad on the ground electrode so both wear surfaces last. That's why these plugs go about 100,000 miles on Honda's maintenance schedule while a nickel plug is done in a third of that. They come pre-gapped at 1.1 mm. Don't touch the gap. Prying on a fine-wire iridium tip is how a new plug dies on the bench.
Thread is 14 mm x 1.25 with a 19 mm reach and a gasket seat, a 5/8 in (16 mm) hex, heat range 6, and a solid terminal. Nothing here is a power add. It's the plug the car was designed around, sold as an engine's worth.
Specs
| Manufacturer Part Number | 5266 (IZFR6K-11S) |
| Hybrid Racing SKU | NGK-5266 |
| Brand | NGK |
| Line | Laser Iridium |
| Quantity | Set of 4 spark plugs, one engine's worth |
| Honda OE cross | 9807B-561BW (IZFR6K-11S NGK) |
| Thread | 14 mm x 1.25, 19 mm reach, gasket seat, per NGK |
| Hex | 5/8 in (16 mm), per NGK |
| Heat range | 6, per NGK |
| Gap | 0.043 in (1.1 mm) as shipped, per NGK. Do not adjust. |
| Center electrode | Iridium, fine wire, 0.6 mm, per NGK |
| Ground electrode | Platinum pad, per NGK |
| Torque | 18-21.6 lb-ft on aluminum heads, per NGK |
| Service life | About 100,000 miles per Honda's maintenance schedule |
| Contents | 4 spark plugs. No coils, boots, or anti-seize. |
Fitment
| Year | Make | Model | Trim | Engine |
| 2006-2011 | Honda | Civic | DX, EX, LX sedan and coupe | 1.8L R18 |
| 2008-2011 | Honda | Civic | EX-L sedan and coupe | 1.8L R18 |
| 2009-2011 | Honda | Civic | LX-S sedan | 1.8L R18 |
This set fits the 2006-2011 Civic DX, LX, LX-S, EX, and EX-L with the 1.8L R18. It does not fit the Civic Si (K20Z3, which takes NGK IFR7G-11KS), the Hybrid, or the GX. A 2012 and newer Civic 1.8 uses a different plug.
What to Know Before You Buy
The 8th gen's coils sit right on top of the valve cover, so this is a driveway job with a 5/8 spark plug socket, an extension, and a torque wrench. Work on a cold engine. Pull one coil, swap one plug, torque it to NGK's 18 to 21.6 lb-ft spec, and move to the next hole so nothing falls into an open tube. Start every plug by hand. Cross-threading an aluminum head turns a 30 minute job into a bad weekend.
While the coils are out, check each boot for tears and look at the spring contacts. A torn boot will misfire right after a plug job and get the new plugs blamed. If your Civic is past 150k and still on original coils, plenty of owners do coils and plugs in one shot. One box, four plugs, and the ignition side is done until well into the next decade of ownership.
This set fits the 2006-2011 Civic DX, LX, LX-S, EX, and EX-L with the 1.8L R18. It does not fit the Civic Si (K20Z3, which takes NGK IFR7G-11KS), the Hybrid, or the GX. A 2012 and newer Civic 1.8 uses a different plug.