Bore, stroke, displacement and compression for all 12 Mercury Duratec engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 140–227 ci |
|---|---|
| Cylinders | 4, 6 |
| Bore | 3.244–3.760" |
| Stroke | 3.130–3.937" |
| Compression | 9.7–10.5:1 |
| Advertised power | 152–305 hp |
| Years | 1999–2019 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 3 7 Duratec V6 | 227 ci | 3.7598" × 3.4134" | 10.5:1 | 305 |
| 3.7L Duratec | 227 ci | 3.7598" × 3.4134" | 10.3:1 | 270–273 |
| Duratec 3.7 | 227 ci | 3.7598" × 3.4134" | — | 304 |
| 3 5 Duratec V6 | 213 ci | 3.6417" × 3.4134" | 10.3:1 | 263 |
| Duratec 3.5 | 213 ci | 3.6417" × 3.4134" | — | 290 |
| 3.0L V6 | 182 ci | 3.5" × 3.2008" | 10:1 | 200 |
| 30 Duratec V6 | 182 ci | 3.5" × 3.2047" | 10:1 | 200 |
| 3.0L Duratec FlexFuel | 182 ci | 3.5" × 3.1969" | 10:1 | 240 |
| Duratec · 3.244" × 3.130" · 9.7:1 | 155 ci | 3.2441" × 3.1299" | 9.7:1 | 170 |
| 2.5L Duratec | 153 ci | 3.5039" × 3.937" | 9.7:1 | 175 |
| 2.5L I4 | 152 ci | 3.5039" × 3.937" | 9.7:1 | 175 |
| 2.3L Duratec | 140 ci | 3.4449" × 3.7008" | 9.7:1 | 152–153 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
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.