See other engines in this family
BMW N20B20 specs: 2.0L (122 ci) 4-cylinder, 84 x 90.1 mm (3.3071 x 3.5472 in) bore and stroke, 10:1 compression. Rated 180-308 hp, 2012–2018.
The BMW N20B20 is undersquare — the 3.5472" stroke exceeds the 3.3071" bore by 6.8% — a layout that trades peak RPM for leverage and torque low in the range. The 3.5472" stroke puts mean piston speed at 4,000 ft/min around 6,750 RPM, which is where a production bottom end is generally considered at its limit. Each of the 4 cylinders displaces 30.5 ci (500 cc).
10:1 is in the range that usually runs on pump premium.
It is one of 7 engines in the BMW 122ci family, all of them 122 ci — the differences between them are in compression, heads and rating, not displacement. 17 factory variants share these dimensions, rated from 180 to 308 hp across 2012–2018.
| Displacement | 122 ci / 2 L |
|---|---|
| Bore | 3.3071" |
| Stroke | 3.5472" |
| Cylinders | 4 |
| Configuration | I4 |
| Compression ratio | 10:1 |
| Bore/stroke ratio | 0.932 |
| Fuel type | gas |
|---|---|
| Advertised HP | 180–308 hp |
| Years | 2012–2018 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. |
|---|---|---|---|---|
| 2012 | N20B20 net | 240 @ 5000 | 255 lb-ft @ 1250 | 10:1 |
| 2013 | N20B20 net | 180 @ 5000 | 200 lb-ft @ 1250 | 10:1 |
| 2013 | N20B20 net | 240 @ 5000 | 255 lb-ft @ 1250 | 10:1 |
| 2014 | N20B20 net | 180 @ 5000 | 200 lb-ft @ 1250 | 10:1 |
| 2014 | N20B20 net | 240 @ 5000 | 255 lb-ft @ 1250 | 10:1 |
| 2015 | N20B20 net | 180 @ 5000 | 200 lb-ft @ 1250 | 10:1 |
| 2015 | N20B20 net | 240 @ 5000 | 255 lb-ft @ 1250 | 10:1 |
| 2016 | N20B20 net | 180 @ 5000 | 200 lb-ft @ 1250 | 10:1 |
| 2016 | N20B20 net | 240 @ 5000 | 255 lb-ft @ 1250 | 10:1 |
Factory specification sheet.
| Bore/stroke character | 0.932 — undersquare — stroke exceeds bore, which favours low-end torque |
|---|---|
| Mean piston speed at 6,000 RPM | 3,547 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 30.5 ci |
| Static compression | 10:1 — in the range that usually runs on pump premium |
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 |
|---|---|---|
| 2012 | — | N20B20 |
| 2012 | 240 hp | N20B20 |
| 2013 | — | N20B20 |
| 2013 | 180 hp | N20B20 |
| 2013 | 240 hp | N20B20 |
| 2014 | — | N20B20 |
| 2014 | 180 hp | N20B20 |
| 2014 | 240 hp | N20B20 |
| 2015 | — | N20B20 |
| 2015 | 180 hp | N20B20 |
| 2015 | 240 hp | N20B20 |
| 2016 | — | N20B20 |
| 2016 | 180 hp | N20B20 |
| 2016 | 240 hp | N20B20 |
| 2016 | 308 hp | N20B20 |
| 2017 | 308 hp | N20B20 |
| 2018 | 308 hp | N20B20 |
5 factory vehicles, 2012–2018. Each year opens that model's engine table.