01 · Overview
The strong naturally aspirated engine without M
With the facelift in spring 2006, BMW reorganised the Z4’s engine lineup. The 3.0si with the N52B30 and 265 PS moved to the top of the series production engines — a straight-six with a magnesium-aluminium crankcase.
For the E86 Coupé, introduced at the same time, it was one of only two engines available; the other was the S54 of the Z4 M. So anyone wanting an E86 without the M surcharge got the 3.0si. Below it, the Roadster offered the 2.5i with 177 PS and the 2.5si with 218 PS.
02 · History
Einordnung
Three dates for context.
- 2006 Facelift of the model line. The 3.0si replaces the 3.0i with M54B30 and 231 PS.
- 2006 The E86 Coupé launches — the 3.0si is the base engine there.
- 2008 End of production of the model line in August.
03 · Engines
Der N52
The successor to the M54 — built lighter, more power.
N52B30 · straight-six verified
Naturally aspirated engine with a composite crankcase of magnesium and aluminium and variable valve timing. Replaced the M54B30 in the Z4, which had produced 231 PS.
Technische Daten anzeigen
| Hubraum | 2.996 cm³ |
| Leistung | 265 PS (195 kW) |
| Vorgänger | M54B30 with 231 PS |
Wikipedia · auto motor und sport
04 · Engineering
Positioning in the lineup
Only two engines in the Coupé
Automatic from the facelift onward
Built in Spartanburg
05 · Buying guide
What matters
The 3.0si is the sensible choice in the model line — powerful enough, without the running costs of an S54.
Electric power steering: a known issue on the Z4. Watch for noise and uneven assistance.
Roadster soft top: check function and seals, especially at the corners of the windscreen.
Standard condition: like others, the 3.0si was frequently lowered and fitted with aftermarket wheels.
06 · The competition
The competition
Porsche Boxster (987)
The benchmark in the segment, with a mid-engine layout and a higher price.
Mercedes-Benz SLK 350 (R171)
V6 with a folding hardtop — set up for more comfort.
07 · Sources
Belege & Literatur
Primary sources are Wikipedia and auto motor und sport; the engine data was cross-checked against the model line page.