Bore, stroke, displacement and compression for all 5 Lexus AR engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 122–165 ci |
|---|---|
| Cylinders | 4 |
| Bore | 3.386–3.543" |
| Stroke | 3.386–4.134" |
| Compression | 10.0–12.5:1 |
| Advertised power | 178–241 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 1AR-FE | 165 ci | 3.5433" × 4.1339" | 10:1 | 182–185 |
| 2AR-FXE | 152.5 ci | 3.5433" × 3.8583" | 12.5:1 | 178 |
| 2AR FE | 152 ci | 3.5433" × 3.8583" | 10.4:1 | 178 |
| 2AR-FSE | 152 ci | 3.5433" × 3.8583" | 12.5:1 | 204 |
| 8AR-FTS | 122 ci | 3.3858" × 3.3858" | 10:1 | 235–241 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 10:1 to 12.5:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
4 of 5 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.