| BMW S68 engine | |
| Manufacturer: | BMW |
| Production: | 2022 - present |
| Displacement: | 4395cc |
| Configuration: | 90° V8 |
| Bore: | 89mm |
| Stroke: | 88.3mm |
| Valvetrain: | DOHC w/ VVT |
| Block: | Aluminium |
| Head: | Aluminium |
| Fueltype: | Petrol |
| 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.[1] A few weeks after its presentation, BMW showed a study of the XM with a more powerful version of the engine.[2] [3] In addition, the basic version is also used in BMW 760i,[4] BMW X5 M60i, and BMW X6 M60i.[5]
The S68 has a stroke of and the same displacement as its predecessor, but the compression ratio of 10.5:1 corresponds to the higher compressed predecessor variants.[6] 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 S68 is the only current production V8 engine offered with a cross-pattern exhaust manifold for improved turbo charger pressure by combining exhaust pulses which comes at an expense of sound alternation, making the sound closer to a 180 degree configuration V8. 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 electric motor with a torque of ; unlike the previous mild hybrid systems from BMW, this is installed within the transmission.[1] 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.[6] [7] the battery required for this has a capacity of 90 Ah.[7] The variable camshaft control (VANOS) is now electrical and no longer hydraulic.[7] The S68 currently meets the Euro 6d emissions standard,[1] [6] but should also be able to achieve the stricter Euro 7 standard, which is planned for 2025.[8] [7]
The electric motor in the S68 has a torque of .[2] [3] A maximum speed of 7200 rpm is reported for the combustion engine.[9]