The X6 xDrive40i is powered by a 3.0-litre turbocharged six-cylinder petrol engine with 48V mild-hybrid technology, producing 381 PS and 540 Nm of torque . It accelerates from 0-100 km/h in 5.4 seconds, with a top speed of 250 km/h . The X6 M features a 4.4-litre V8 M TwinPower Turbo engine delivering 575 hp and 0-100 km/h in 4.2 seconds .