BMW currently offers four distinct powertrain architectures — pure internal combustion (ICE), 48V mild hybrid (MHEV), full battery electric (BEV), and the upcoming Neue Klasse platform. Each serves a different purpose, but all share BMW's engineering philosophy of prioritising driving dynamics above all else. Here's how they work.
The S58: BMW's Legendary Twin-Turbo Inline-Six
The heart of every current M car is the S58 3.0-litre twin-turbocharged inline-six. In the M3 Competition, it produces 503 horsepower and 479 lb-ft of torque. The M2 gets a detuned version making 473 hp (up from 453 for 2025), while the M3 CS pushed output to 543 hp. BMW's commitment to the straight-six dates back to the 1968 BMW 2500 and continues through every generation of M car. The configuration offers inherent balance — primary and secondary forces cancel naturally, producing smooth power delivery without balance shafts.
M xDrive: Three Modes of All-Wheel Drive
BMW's M xDrive system offers three selectable modes: 4WD (standard rear-biased AWD), 4WD Sport (allows more rear slip before engaging the front axle), and 2WD (pure rear-wheel drive with the front axle mechanically disconnected). The transfer case uses a chain drive rather than pinion gears for reduced noise and drag, with a multi-clutch coupling that varies torque distribution continuously. Response times are remarkable: less than 150 milliseconds for torque variation, and under 400 milliseconds to return from efficiency mode. During highway cruising, the system automatically decouples the front axle entirely.
M Traction Control: 10 Levels of Slip
Available on M3/M4 Competition models when DSC is fully disabled, M Traction Control provides 10 levels of rear-wheel slip management. Level 0 is fully off, allowing unlimited wheel spin for drifting. Higher levels progressively restrict slip for better traction. The system is unique in that it controls slip exclusively through engine RPM — vehicle yaw rate is not a controlled variable, unlike the standard DSC/MDM systems. This makes it a fundamentally different tool: where MDM uses both engine power and brake interventions to control the car's attitude, M Traction Control simply manages how much the rear tyres are allowed to break traction.
48V Mild Hybrid (MHEV): Invisible Electrification
The X5 xDrive40i and 760i xDrive use BMW's 48V mild hybrid system paired with the B58 turbocharged inline-six. The 48V system adds an integrated starter-generator that provides electric boost during acceleration, enables engine-off coasting at highway speeds, and recovers energy during braking. In the X5, this combination produces 375 hp and 398 lb-ft; in the 760i, a twin-turbo V8 variant delivers 536 hp and 553 lb-ft. The mild hybrid operates transparently — most drivers won't even notice it's there, which is precisely the point.
