Bore, stroke, displacement and compression for all 17 Mercedes-Benz 183ci engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 183 ci |
|---|---|
| Cylinders | 5, 6 |
| Bore | 3.268–3.583" |
| Stroke | 3.232–3.638" |
| Compression | 10.5–22.0:1 |
| Advertised power | 77–577 hp |
| Years | 1978–2026 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| OM617.912 (3005 cc) | 183 ci | 3.5827" × 3.6378" | — | 77 |
| OM617.912 (2998 cc) | 183 ci | 3.5787" × 3.6378" | — | 77 |
| M272 | 183 ci | 3.4646" × 3.2323" | — | — |
| M276 | 183 ci | 3.4646" × 3.2323" | 10.5:1 | 329–396 |
| OM617.952 | 183 ci | 3.5787" × 3.6378" | 21.5:1 | — |
| OM603.960 | 183 ci | 3.4252" × 3.3071" | 22:1 | — |
| OM606.910 | 183 ci | 3.4252" × 3.3071" | — | — |
| OM606 | 183 ci | 3.4252" × 3.3071" | — | 134–174 |
| M276 DE30 LA | 183 ci | 3.4646" × 3.2323" | — | — |
| M256 | 183 ci | 3.2677" × 3.6378" | 10.5:1 | 362–429 |
| M256M | 183 ci | 3.2677" × 3.6378" | 10.5:1 | 375 |
| M256 + electric motor | 183 ci | 3.2677" × 3.6378" | 10.5:1 | 577 |
| OM617.950 | 183 ci | 3.5827" × 3.6378" | 21.5:1 | — |
| OM617.951 | 183 ci | 3.5787" × 3.6378" | 21.5:1 | — |
| OM603.961 | 183 ci | 3.4252" × 3.3071" | 22:1 | — |
| M276 + e-motor | 183 ci | 3.4646" × 3.2323" | 10.7:1 | — |
| M256 + e-motor | 183 ci | 3.2677" × 3.6378" | 10.5:1 | — |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 10.5:1 to 22:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
The family mixes oversquare and undersquare designs, so members behave quite differently despite sharing a name.
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.