Bore, stroke, displacement and compression for all 3 BMW N54/B58 engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 182.7 ci |
|---|---|
| Cylinders | 6 |
| Bore | 3.228–3.307" |
| Stroke | 3.528–3.724" |
| Compression | 9.4–11.0:1 |
| Advertised power | 302–382 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| N54B30 | 182.7 ci | 3.3071" × 3.5276" | 10.2:1 | 302 |
| N54B30 | 182.7 ci | 3.3071" × 3.5276" | 9.4:1 | 360 |
| N54/B58 · 3.228" × 3.724" · 11:1 | 182.7 ci | 3.2283" × 3.7244" | 11:1 | 322–382 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 9.4:1 to 11:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
All are undersquare — stroke larger than bore, favouring torque low in the range.
Each engine page carries rod ratio, mean piston speed, bore/stroke character and cylinder head specs where published, and links into the calculators with its dimensions already filled in.