Toyota BMW B48/B58 (Supra) specs: 82 x 94.6 mm (3.2283 x 3.7244 in) bore and stroke, shared by all 4 versions. Displacement, compression and factory ratings.
| Displacement | 121.9–182.9 ci |
|---|---|
| Cylinders | 4, 6 |
| Bore | 3.228" |
| Stroke | 3.724" |
| Compression | 10.2:1 |
| Advertised power | 255–382 hp |
| Years | 2020–2026 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| B58B30 | 182.9 ci | 3.2283" × 3.7244" | — | — |
| B58B30 | 182.9 ci | 3.2283" × 3.7244" | — | 335–382 |
| B48B20 | 121.9 ci | 3.2283" × 3.7244" | 10.2:1 | — |
| B48B20 | 121.9 ci | 3.2283" × 3.7244" | 10.2:1 | 255 |
All are undersquare — stroke larger than bore, favouring torque low in the range.
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.