BMW S68
| BMW S68 engine | |
|---|---|
 S68 in BMW XM (G09) | |
| Overview | |
| Manufacturer | BMW |
| Production | 2022–present |
| Layout | |
| Configuration | 90° V8 |
| Displacement | 4.4 L (4,395 cc) |
| Cylinder bore | 89 mm (3.50 in) |
| Piston stroke | 88.3 mm (3.48 in) |
| Cylinder block material | Aluminium |
| Cylinder head material | Aluminium |
| Valvetrain | DOHC w/ VVT |
| Combustion | |
| Fuel type | Petrol |
| Chronology | |
| Predecessor | BMW S63 |
The BMW S68 is a twin-turbocharged V8 engine produced by BMW. Its first use was in the 2022 revised BMW X7 as the M60i. A few weeks after its presentation, BMW showed a study of the XM with a more powerful version of the engine. In addition, the basic version is also used in BMW 760i, BMW X5 M60i, and BMW X6 M60i.
Design
The S68 has a stroke of 88.3 mm (3.48 in) and the same displacement as its predecessor, but the compression ratio of 10.5:1 corresponds to the higher compressed predecessor variants. It has one turbocharger per cylinder bank and both chargers are placed in the middle of the cylinder banks in a hot-vee design taken from the previous S63 variant; there is only one exhaust manifold. The engine oil is cooled by an external cooler, and a newly developed oil pump is used for the oil circuit. The engine is now only offered as a 48-volt mild hybrid powerplant mild hybrid system, it has a 9 kW (12 hp) electric motor with a torque of 200 N⋅m (150 lbf⋅ft); unlike the previous mild hybrid systems from BMW, this is installed within the transmission. The electric motor is also used for hot starts, while cold starts are performed by a standard 12 volt starter similar to most other engines. The 48-volt battery found in the X7 M60i, XM, and the 760i models has a capacity of 20 Ah. the battery required for this has a capacity of 90 Ah. The variable camshaft control (VANOS) is now electrical and no longer hydraulic. The S68 currently meets the Euro 6d emissions standard, but should also be able to achieve the stricter Euro 7 standard, which is planned for 2025.
The electric motor in the S68 has a torque of 200 N⋅m (150 lbf⋅ft). A maximum speed of 7200 rpm is reported for the combustion engine.