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Porsche M96.20 specs: 2.5L (151.34 ci) 6-cylinder, 85.5 x 72 mm (3.3661 x 2.8346 in) bore and stroke, 11:1 compression. Rated 201 hp, 1997–1999.
The Porsche M96.20 is oversquare — the 3.3661" bore exceeds the 2.8346" stroke by 18.8% — a layout that favors airflow and RPM over leverage at the crank. The 2.8346" stroke does not reach 4,000 ft/min of mean piston speed until about 8,450 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 6 cylinders displaces 25.2 ci (413 cc).
11:1 is high enough that pump premium or better is normally required.
It is one of 11 engines in the M96 family, the smallest at 151.34 ci. 3 factory variants share these dimensions, rated at 201 hp across 1997–1999.
| Displacement | 151.34 ci / 2.5 L |
|---|---|
| Bore | 3.3661" |
| Stroke | 2.8346" |
| Cylinders | 6 |
| Compression ratio | 11:1 |
| Bore/stroke ratio | 1.188 |
| Fuel type | gas |
|---|---|
| Firing order | 1-6-2-4-3-5 |
| Advertised HP | 201 hp |
| Years | 1997–1999 |
| Bore/stroke character | 1.188 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 2,835 ft/min — conservative for a street engine |
| Displacement per cylinder | 25.2 ci |
| Static compression | 11:1 — high enough that pump premium or better is normally required |
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 |
|---|---|---|
| 1997 | 201 hp | M96.20 |
| 1998 | 201 hp | M96.20 |
| 1999 | 201 hp | M96.20 |
1 factory vehicle, 1997–1999. Each year opens that model's engine table.