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Spark plugs BMW 3 Series E90 N52B25 (2.5i) — NGK, Bosch, Denso

Spark plugs for BMW 3 Series E90 N52B25 (2.5iL, 2005–2011) — OEM-spec NGK, Bosch, Denso and Champion part numbers with replacement interval.

Engine Specifications

ParameterValue
Make / ModelBMW 3 Series E90
Engine CodeN52B25
Displacement / Fuel2.5iL petrol
Production Years2005–2011
Plug typeiridium
ThreadM14x1.25
Reach26.5 mm
Hex size16 mm
Electrode gap0.7 mm
Heat range7

Compatible Spark Plugs

BrandPart NumberType
NGKNGK ZGR6STE2OE supplier
BoschBosch 0242230506OE supplier
DensoDenso IXU22OE supplier
ChampionChampion RC10YP4aftermarket

Replacement Interval

ParameterValue
Mileage60 000 km
Time4 years

Iridium and platinum plugs last 2–3× longer than standard copper plugs. Replace them on schedule — worn plugs increase fuel consumption by 3–5% and reduce power output.

Choosing Spark Plugs for N52B25

  1. Use the correct plug type — the N52B25 requires iridium plugs. Upgrading from standard to iridium is acceptable.
  2. Check the electrode gap — verify the gap is 0.7 mm before installation.
  3. Torque correctly — for M14x1.25 thread: aluminium head 20–25 Nm, cast iron head 25–30 Nm.
  4. Replace as a full set — always replace all cylinders at once to ensure even combustion across all cylinders.

FAQ

Which spark plugs fit BMW 3 Series E90 N52B25?

NGK NGK ZGR6STE2, Bosch Bosch 0242230506, Denso Denso IXU22. All three are OE suppliers and guarantee compatibility with this engine.

How often should spark plugs be replaced on BMW 3 Series E90?

Every 60 000 km or 4 years, whichever comes first. Iridium plugs (NGK ZGR6STE2) have a longer service life compared to standard nickel plugs.

Can I fit a different type of spark plug in the N52B25?

Upgrading to iridium or platinum is acceptable and gives a slight improvement in cold starts. Do not change the heat range (7) — an incorrect heat range can cause pre-ignition or fouling.