Porsche 275ci specs: 93 x 83 mm (3.6614 x 3.2677 in) bore and stroke, shared by all 2 versions. Displacement, compression and factory ratings, plus rod ratio.
| Displacement | 275 ci |
|---|---|
| Cylinders | 8 |
| Bore | 3.661" |
| Stroke | 3.268" |
| Compression | 9.5–11.5:1 |
| Advertised power | 340–450 hp |
| Years | 2003–2006 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| M48.00 | 275 ci | 3.6614" × 3.2677" | 11.5:1 | 340 |
| M48.50 | 275 ci | 3.6614" × 3.2677" | 9.5:1 | 450 |
Compression spans 9.5:1 to 11.5:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
All are oversquare — bore larger than stroke, which favours revs over low-end torque.
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.