Bore, stroke, displacement and compression for all 37 Subaru EJ engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 91.1–152 ci |
|---|---|
| Cylinders | 4 |
| Bore | 3.268–3.917" |
| Stroke | 2.591–3.110" |
| Compression | 8.0–10.0:1 |
| Advertised power | 90–341 hp |
| Years | 2002–2021 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| EJ · 3.917" × 3.110" · 8.2:1 | 152 ci | 3.9173" × 3.1102" | 8.2:1 | 210–300 |
| EJ255 | 152 ci | 3.9173" × 3.1102" | 8.4:1 | 250 |
| EJ · 3.917" × 3.110" · 10:1 | 152 ci | 3.9173" × 3.1102" | 10:1 | 165–175 |
| EJ255 | 150.2 ci | 3.9173" × 3.1102" | 8.4:1 | 250 |
| EJ257 | 150.2 ci | 3.9173" × 3.1102" | 8.2:1 | 300 |
| Ej25 S NA | 150.2 ci | 3.9173" × 3.1102" | 10:1 | 165 |
| EJ257 | 150.2 ci | 3.9173" × 3.1102" | — | 300–341 |
| EJ255 | 150.2 ci | 3.9173" × 3.1102" | — | 224–265 |
| EJ255 | 150 ci | 3.9173" × 3.1102" | 8.4:1 | 224 |
| EJ · 3.917" × 3.110" · 10:1 | 150 ci | 3.9173" × 3.1102" | 10:1 | 165–175 |
| EJ257 | 150 ci | 3.9173" × 3.1102" | 8.2:1 | 250–300 |
| EJ25 | 149.9 ci | 3.9173" × 3.1102" | 10:1 | 165 |
| Ej25t | 149.9 ci | 3.9173" × 3.1102" | 8.2:1 | 305 |
| EJ22E | 135 ci | 3.815" × 2.9528" | 9.5:1 | 130–135 |
| EJ22G | 135 ci | 3.815" × 2.9528" | 8:1 | 160–280 |
| EJ222 | 135 ci | 3.815" × 2.9528" | 10:1 | 142 |
| 22 NA | 134.9 ci | 3.815" × 2.9528" | 9.5:1 | 135 |
| 22 Turbo | 134.9 ci | 3.815" × 2.9528" | 8:1 | 160 |
| EJ · 3.622" × 2.953" · 8:1 | 122 ci | 3.622" × 2.9528" | 8:1 | 220–280 |
| EJ20 (NA DOHC) | 122 ci | 3.622" × 2.9528" | 10:1 | 155 |
| EJ20 (NA SOHC) | 122 ci | 3.622" × 2.9528" | 9.7:1 | 125 |
| EJ20Y/X | 122 ci | 3.622" × 2.9528" | 9.5:1 | 250 |
| EJ205 | 122 ci | 3.622" × 2.9528" | — | 227 |
| EJ20 (SOHC NA) | 121.9 ci | 3.622" × 2.9528" | 9.7:1 | 125 |
| EJ20 (DOHC NA) | 121.9 ci | 3.622" × 2.9528" | 10:1 | 155 |
| EJ20G | 121.9 ci | 3.622" × 2.9528" | 8.5:1 | 220 |
| EJ · 3.622" × 2.953" · 8:1 | 121.9 ci | 3.622" × 2.9528" | 8:1 | 227–280 |
| 20 NA Sohc | 121.7 ci | 3.622" × 2.9528" | 9.7:1 | 125 |
| EJ · 3.622" × 2.953" · 8:1 | 121.7 ci | 3.622" × 2.9528" | 8:1 | 220–280 |
| EJ20D | 121.7 ci | 3.622" × 2.9528" | 10:1 | 150–155 |
| EJ20Y/X | 121.7 ci | 3.622" × 2.9528" | 9.5:1 | 250 |
| 18 NA | 111.1 ci | 3.4606" × 2.9528" | 9.5:1 | 110 |
| EJ18 | 110.8 ci | 3.4606" × 2.9528" | 9.5:1 | 110 |
| EJ16 | 97.6 ci | 3.3071" × 2.8346" | 9.7:1 | 90 |
| 16 NA | 97.5 ci | 3.4606" × 2.5906" | 9.7:1 | 90 |
| EJ15 | 91.5 ci | 3.2677" × 2.7244" | 9.5:1 | 97 |
| 15 NA | 91.1 ci | 3.3465" × 2.5906" | 9.5:1 | 97 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 8:1 to 10:1, 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.