PORSCHE’S Cayenne Turbo, the Mercedes-Benz ML 63 AMG and the Audi Q7 V12 TDI have a crushing new competitor in the (unusual) shape of the BMW E71 X6 M.

Priced from $179,900, it is to be joined from January by the $172,900 E70 X5 M that shares many of the same underpinnings and driving gear but then diverges with a different body style and five rather than four seats.

However, both pack a mighty wallop thanks to a 4.4-litre twin-turbo V8 petrol engine.

That’s right. Along with the fact that this BMW is a. an SUV, b. all-wheel drive, and c. not built in Germany (Spartanburg, USA gets the gig), the X6 M and its more conventional looking sibling radically departure from M GmbH policy in eschewing natural aspiration for forced-induction performance.

Or, in other words, both the X5 M and X6 M make nice with a turbo … twice.

Dubbed M TwinPower Turbo this Euro 5 emissions-rated 4395cc V8 delivers 408kW of power at 6000rpm and 680Nm of torque from 1500 to 5650rpm.

Aiding this is a production engine world-first common exhaust emission manifold that joins both rows of cylinders to the twin-scroll turbo set-up. Along with the catalytic converters, the turbos are positioned in the V-section between the cylinder rows for faster and more efficient response times.

As a result, BMW says, lag has been all but eliminated.

In contrast, rival outputs are 375kW/630Nm (ML 63 AMG), 404kW/750Nm (Cayenne Turbo), 368kW/1000Nm (Q7 V12 TDI) and 375kW/625Nm (Range Rover Sport S/C V8).

This 2305kg SUV’s acceleration from standstill to 100km/h takes 4.7 seconds (0.1s faster than a Cayenne Turbo) and top speed is limited to 250km/h, while the 14.3 litres per 100 kilometres fuel-consumption average is better than the BMW’s (petrol-powered) rivals (the Audi returns 11.3L/100km). So is the 335 grams per kilometre carbon dioxide emissions rating (Audi excepted: 298g/km).

The latter is a result of BMW’s EfficientDynamics philosophy – which sees the inclusion of Brake Energy Regeneration, an on-demand fuel pump, a detachable air-conditioner compressor and a volume flow-controlled supply of the hydraulic fluid that goes to the active anti-roll system.

An M-massaged ZF six-speed automatic gearbox with paddle shifters makes for “extremely short gearshift times (due to) an innovative torque reduction concept which briefly cancels out fuel injection and ignition” – the company states.

Drive is to all four wheels, distributed continuously according to how the road, conditions and driving style dictates – up to 100 per cent of torque can even be delivered to the front wheels if necessary – via a centrally mounted and electronically activated multi-plate clutch. Overseeing these are stability and traction controls and advanced anti-lock and brake technology systems, collectively known as DSC+ in BMW-speak.

The M-SUV continues with a variation of the X6’s Dynamic Performance Control (DPC) rear differential that counteracts the inherent mild understeer for a more rear-wheel-drive-centric neutral attitude through quick turns and manoeuvres.

It does this by oscillating torque between the left and right rear wheels for improved traction and lateral acceleration, leading to lighter and more precise handling.

The X6 M’s suspension is a double wishbone arrangement up front and a variation of BMW’s Integral IV axle multi-link set-up in the rear.

Electronic dampers are fitted, as well as BMW’s Dynamic Drive technology with self-levelling air suspension out back. Stiffer shockers, modified anti-roll bars and a 10mm ride height drop are also part of the X6 M’s standard specification.

Brakes are by 19-inch high-performance items using lightweight technology with ‘virtually’ no fading, BMW says.

Steering is a hydraulically powered Servotronic system that’s also been fettled by M GmbH to include a ‘Sports Mode’ setting via an M Drive button known as MDM M Dynamic Mode, – which also raises the threshold of both brake intervention and the engine power delivery management, while allocating a more rear-drive bias for improved high-speed cornering and control capabilities.

No other BMW M model has had Runflat tyres before, but oddly a spare is also fitted. Tyres are 275/40 R20s in the nose and a set of 315/35 R20s behind.

Standard features include Bi-Xenon high intensity discharge adaptive headlights with a daytime driving function, adaptive brake lights, an alarm, sunroof, high-gloss trim, metallic paint, head-up display, Comfort Access lighting, sports heated front seats, sports steering wheel, M Sport trim and specific M Sport instrumentation.

BMW will not talk sales figures, but says the X6 M should establish a comfortable enough niche to take on the Cayenne Turbo.