Lexus NX Spark Plugs: Intervals, Fitment & Warning Signs
A genuinely important, official instruction: Lexus explicitly states not to adjust the gap on Denso iridium plugs, since the fragile tip can break or chip.
Illustration for editorial purposes
Opens live listings in a new tab.
OEM Part Number: confirm via engine code — aftermarket NGK 5989 / Bosch 0 242 129 529
| Petrol engines in this generation | NX 200, NX 200t, NX 300, NX 300h (petrol/electric), some AWD versions; no engine code is attached to individual plugs |
|---|---|
| Spark plugs (aftermarket) | NGK 5989 (iridium, M12x1.25, 14 mm hex); NGK 4912 (iridium, M12x1.25, 14 mm hex); NGK 94697 (iridium, 0.8 mm gap, M14x1.25, 16 mm hex); NGK 91961 (iridium, M14x1.25, 16 mm hex); Denso IXEH20TT (iridium centre, platinum earth, M12x1.25); Denso FK16HR-A8 (M14x1.25; OE 90919-01259); Champion CCH9412 (iridium, 1.0 mm gap, M12x1.25, 14 mm hex) |
| Genuine (OE) numbers quoted | Denso FK16HR-A8 = 90919-01259 |
| Fitment notes | Two plug families appear: M12x1.25 / 14 mm hex (NGK 5989 and 4912, Denso IXEH20TT, Champion CCH9412) and M14x1.25 / 16 mm hex (NGK 94697 and 91961, Denso FK16HR-A8, Champion CCH9006); the plugs are not tied to the 200t (turbo) versus the 300h, so check the engine before ordering. Mostly iridium; no change interval is given. |
Lexus NX Spark Plugs: A Cheap Part That Causes Expensive-Feeling Problems
Worn spark plugs on the Lexus NX rarely announce themselves clearly — a slightly rougher idle, a bit less punch off the line — symptoms easy to blame on almost anything else in the engine bay. The part itself costs very little, which makes it an easy one to overlook for far longer than it should be.
Lexus NX Spark Plugs: What They Do
The Lexus NX's spark plugs ignite the compressed fuel-air mixture inside each cylinder, and their condition directly affects combustion efficiency, fuel economy and smooth running. Petrol engines rely entirely on them; diesel engines don't use spark plugs at all, relying on compression instead.
Lexus NX Spark Plugs: Generations & Spark Plug Count
| Diesel variants, where fitted | Not applicable — diesel engines use compression ignition and have no spark plugs at all |
|---|---|
| Petrol variants (all trims) | 4 spark plugs — one per cylinder |
Lexus NX Spark Plugs: Watch: Replacing It
NX200t turbo; 2015-2021 version: M2M2rTinE6_9w.
Opens live listings in a new tab.
A Genuinely Important, Official Instruction Worth Knowing — Lexus NX Spark Plugs
This is genuinely worth knowing before fitting Denso iridium spark plugs: Lexus explicitly states not to adjust the gap on these plugs during installation, since the iridium tip is genuinely fragile and adjusting the gap risks breaking or chipping it.
It's also genuinely worth knowing a useful diagnostic technique: swapping coil packs between cylinders and seeing whether the misfire code follows the coil can help confirm whether a specific coil is genuinely at fault.
Lexus NX Spark Plugs: Warning Signs, DIY Difficulty & Aftermarket Advice
These are the same regardless of make or model — see our full Spark Plugs Guide for symptoms of worn plugs, why matching your exact plug specification matters, and trusted brands to buy from.
More Lexus Spark Plugs
The same part, covered across other Lexus models.