Woodcliff Lake, New Jersey - When BMW's M division unleashed its first X cars, the X5 M and X6 M in 2009, purists threw up their hands in horror.
But the X6 M in particular belied its somewhat ungainly looks with no-nonsense muscle and unexpected agility - and now the M boffins have upped the ante with a new pair of X siblings, due to debut at the Los Angeles motor show in the last week of November and scheduled for South African release in April 2015.
They share what Munich says is the most powerful engine yet in an all-wheel drive BMW - a 4.4-litre, direct-injection, biturbo V8 quoted at 423kW from 6000-6500 revs (three percent up on the previous version) and 750Nm (a 10 percent boost) from 2200 to 5000rpm.
It's claimed to be capable of pushing either of these two-ton-plus muscle-wagons from standstill to 100km/h in 4.2 seconds, driving through a new eight-speed Steptronic paddle-shift auto transmission that's programmed with Drivelogic software to feel like a dual-clutch 'box without the extra weight and complexity.
The xDrive system uses an electronically controlled multi-plate clutch to distribute the drive, from 100 percent at the rear to 100 percent front-wheel drive depending on where the traction is (although the default setting is a slightly rear-biased torque split) while upgraded stability-control software uses selective braking keep the car going in the direction at which it's pointed.
STRAIGHT OUT OF THE M CATALOGUE
Stability control is switchable from the nanny setting, to MDM (dynamic mode) which allows the car to get a little out of shape, to 'Off' (not quite what it says on the tin) which will let you get yourself into a lot of trouble but will eventually intervene.
All of which rolls on revised suspension, lowered by 10mm from the vanilla-flavour X5 and X6, with increased camber, stiffer bushings and self levelling rear air suspension as standard issue - as are yaw control to reduce body roll in cornering and three-way switchable damping; 21” rims are shod with 285/35 front and 325/30 rear run-flats.
Six-piston callipers, finished in a distinctive metallic blue with the M logo in front, grab cast-iron discs with 50 percent more swept area than previously for plenty of Brick Wall Effect and resistance to fade.
Interior décor is straight out of the M catalogue, including special M instrument cluster, leather steering wheel with aluminium shift paddles and power-adjustable sports seats, all trimmed in merino leather with contrast stitching and embossed M logos, aluminium accents and an anthracite headliner in alcantara synthetic suede.
Standard kit includes a power-operated tailgate, adaptive xenon headlights, automatically dimming mirrors all round, four-zone aircon, rear-view camera, Harman Kardon surround sound, satnav and ConnectedDrive online - and a Laptimer app for your smartphone, so you can share you telemetry analysis over a cold one in the pub, or over social networks.