Above all else, M division claims to cherish the harmony of a vehicle’s components. In that respect, twinning the fearsome 4.4-litre V8 to BMW’s xDrive all-wheel drive system makes sense.
In contrast to the rear-drive M5, which uses the same engine but loses traction more quickly than you’d misplace a set of see-through house keys, the latest X5’s ability to send up to 100% of available torque to either axle (and side to side at the rear via the diff-mimicking Dynamic Performance Control) gives it a clear and obvious advantage over the saloon.
The benefits of an SUV’s hereditary drivetrain are chiefly what permits an additional upgrade of the V8’s output. Consequently, where the X5 M started with 547bhp and 502lb ft (essentially where the M5 remains), it now has 567bhp and 553lb ft.
This is the result of higher cylinder pressures produced by the 200bar fuel injectors and twin-scroll turbochargers (fed from a cross-bank manifold), made possible by a supremely rigid forged crankshaft and closed-deck crankcase.
Also new to the X5 M is the eight-speed M Steptronic automatic gearbox, which replaces the old six-speeder. It’s a torque converter rather than dual-clutch automatic unit, and it’s in the far wider ratio spread afforded by it that M division has found much of its efficiency savings. BMW quotes 20 per cent improvements for both economy and emissions, with the 258g/km CO2 output making the X5 M a full 40g/km cleaner than the Range Rover Sport SVR.