For some strange reason – I can’t think why – BMW has decided to release performance versions of their monolithic X5 and anti-establishment X6. Developed and tweaked by the firm’s famed M Division these two monsters have received some serious firepower in the form of a brand new twin-turbocharged V8 engine. Not only does it thump out an incredible 408 kilowatts between 5750 – 6000rpm, it’s also the first power unit in the world to feature a common exhaust emission manifold joining both rows of cylinders as well as twin scroll twin-turbo technology. In english this means that both these heavyweights will now hurtle from 0-100km/h in a mere 4.7-seconds and carry on to a license-revoking top speed of 250km/h (275km/h if you specify the optional M Driver’s Package). To cope with the 680Nm of torque that’s available from 1500 – 5650rpm, BMW’s engineers have mated the uber-engine to a heavy-duty six-speed M Sports Automatic transmission that incorporates a launch control system for maximum off-the-line acceleration. Riding atop standard 20-inch light alloy rims, both the BMW X5 M and BMW X6 M should be rolling into the market at the end of the year. Although why you’d actually pick either one of them over an M3 or M6, god only knows.