The BMW S68 is a twin-turbochargedV8 engine produced by BMW. Its first use was in the 2023 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]
Design
The S68 has the same piston stroke of 88.3mm (3.48in) and displacement as its S63 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 turbochargers 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 9kW (12hp) electric motor with a torque of 200N⋅m (150lbf⋅ft); 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 battery required for this has a 90 Ah capacity. The 48-volt battery found in the X7 M60i, XM, and the 760i models has a capacity of 20 Ah.[6][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 200N⋅m (150lbf⋅ft).[2][3] Maximum revs are 7200 rpm.[9]
