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Saab B258i specs: 2.5L (153 ci) 6-cylinder, 81.6 x 79.6 mm (3.2126 x 3.1339 in) bore and stroke. Rated 170 hp, 1994–1997. Used in the Saab 900.
The Saab B258i is close to square: 3.2126" bore against 3.1339" stroke, within 2.5%, which splits the difference between a high-revving layout and a torque layout. The 3.1339" stroke does not reach 4,000 ft/min of mean piston speed until about 7,650 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 6 cylinders displaces 25.5 ci (418 cc).
4 factory variants share these dimensions, rated at 170 hp across 1994–1997.
| Displacement | 153 ci / 2.5 L |
|---|---|
| Bore | 3.2126" |
| Stroke | 3.1339" |
| Cylinders | 6 |
| Configuration | V6 |
| Bore/stroke ratio | 1.025 |
| Fuel type | gas |
|---|---|
| Advertised HP | 170 hp |
| Years | 1994–1997 |
| Bore/stroke character | 1.025 — square — bore and stroke are within 5%, a balanced compromise |
|---|---|
| Mean piston speed at 6,000 RPM | 3,134 ft/min — conservative for a street engine |
| Displacement per cylinder | 25.5 ci |
Each link opens the calculator with this engine's specs already filled in.
These records share identical bore, stroke, displacement and compression. They differ by model year and factory power rating.
| Year | Advertised HP | Code |
|---|---|---|
| 1994 | — | B258i |
| 1995 | 170 hp | B258i |
| 1996 | — | B258i |
| 1997 | — | B258i |
1 factory vehicle, 1994–1997. Each year opens that model's engine table.