01 · Overview
The M3 engine in the Roadster
The Z4 M took over the S54B32 from the M3 E46 — the same inline six that had been named “International Engine of the Year” five times in a row. 343 PS at 7,900 rpm, 365 Nm, and according to BMW, eighty percent of the torque is already available at 2,000 rpm.
What’s notable is what’s missing: a sequential gearbox. The SMG was available for the other M models of those years, but not for the Z4 M. It remained manual only. Externally, revised aprons, a contoured bonnet and four tailpipes set it apart from the rest of the Z4 range.
02 · History
Einordnung
Three data points for context.
- 2006 The Z4 M arrives alongside the revised Roadster — the top of the model line.
- 2006 The Z4 M Coupé (E86) joins the same year, technically identical but stiffer.
- 2008 End of production for the series in August; successor is the E89 with folding hardtop.
03 · Engines
Der S54
A high-revving naturally aspirated engine that came from the M3 and found its last production car home in the Z4.
S54B32 · Inline six-cylinder verified
The same engine as in the M3 E46 and the Z3 M of the final model years. Naturally aspirated with individual throttle bodies, eager to rev up to 8,000 rpm. The Z4 M was the last production BMW to offer it.
Technische Daten anzeigen
| Hubraum | 3.246 cm³ |
| Leistung | 343 PS (252 kW) at 7,900 rpm |
| Drehmoment | 365 Nm |
| Getriebe | 6-Gang-Handschaltung |
BMW M · Wikipedia
04 · Engineering
What defines the Z4 M
No SMG
Erkennungsmerkmale
Built in Spartanburg
05 · Buying guide
What matters most
The S54 is the heart of the car — and the rod bearing question follows it just as it does the M3 E46.
Rod bearings: the best-known issue with the S54. Ask for proof of work carried out.
VANOS: rattling on cold start and a rough idle point to the variable valve timing unit.
Check for original condition: the Z4 M is often lowered and fitted with aftermarket wheels.
06 · The competition
The Competition
Porsche Boxster S (987)
Mid-engine versus front-engine — the most obvious rival of the time.
Mercedes-Benz SLK 55 AMG (R171)
V8 instead of inline six, folding hardtop instead of a soft top.
07 · Sources
Belege & Literatur
Primary sources are BMW M and BMW Group Classic, cross-checked against Wikipedia and the trade press.