THE new BMW X6 Sports Activity Coupe making its debut at next week's North American motor show in Detroit heralds the dawn of a new era in motoring. Never before have the elegant flowing lines of a coupe been combined with the powerful presence of an off-road style four-wheel-drive model.

The BMW X6 is the third X model to be launched by BMW, and priced from just under £42,000.

The four-seater is aimed at a different customer to X3 and X5 owners, appealing to the driver who enjoys the command driving position, but one that also savours the characteristics of a sports car.

The BMW X6 launches here in May, with the X6 xDrive30d, xDrive35i and xDrive35d. The X6 xDrive50i goes on sale later in the year. Prices for this model will be announced nearer the time.

For the first time in BMW's history, an entire model range is turbocharged with the X6 offering a quartet of forced induction powerplants - two petrol and two diesel.

While there is nominal performance difference between comparative 3.5 litre diesel and petrol models, the diesels are not only hugely more economical on fuel, they also carry only standard Congestion Charge rates and £210 road tax from April against the punitive top CC rate and £400 VED of the petrol versions.

The range flagship will be an all-new twin-turbocharged petrol V8 producing 408hp and its 600Nm of torque from 1,800rpm through to 4,500rpm propels the X6 from 0-62mph in 5.4 seconds. Top speed has been electronically-limited to 155mph. Fuel consumption on the combined cycle is 22.6mpg.

To optimise packaging, the configuration of the new V8 engine is unique - the first engine in the world to locate twin-turbochargers and a catalytic converter within the vee of the engine.

To complement the outstanding performance figures of the new 4.4 litre twin-turbocharged X6, it is joined by the X6 xDrive35i powered by the International Engine of the Year 2007 winning 3.0 litre twin-turbocharged six-cylinder petrol engine already available in the 1 and 3 Series.

The 306hp £42,625 BMW X6 xDrive35i produces peak torque of 400Nm from 1,300rpm through to 5,000rpm for a seamless wave of acceleration. It can sprint from 0-62mph in 6.7 seconds before going on to a top speed of 149mph. Fuel consumption on the combined cycle is 25.9mpg with CO2 emissions of 262g/km.

It is the diesel-powered cars that are predicted to be the biggest selling variants in the UK.

The £41,955 BMW X6 xDrive30d is powered by a single-turbocharged six-cylinder diesel engine producing 235hp for a zero to 62mph time of eight seconds and top speed of 137mph yet still achieves 34.4mpg on the combined cycle.

Blending high performance with class-leading fuel economy and CO2 emissions is also a trait of the BMW X6 xDrive35d.

Powered by an award-winning twin-turbocharged six-cylinder diesel engine, the X6 xDrive35d produces 286hp and 580Nm for 0-62mph in 6.9 seconds and a top speed of 147mph. Fuel consumption is equally impressive with 34.0mpg on the combined cycle and 220g/km CO2 emissions.

Twinned with BMW's benchmark xDrive four-wheel-drive system, dynamic performance control makes its world debut on the BMW X6. Dynamic performance control improves driving stability at all speeds.

All BMW X6s models come with 19in alloy wheels, dynamic performance control, xDrive four-wheel-drive, dynamic stability control+, xenon headlights, front and rear park distance control, sports suspension and a six-speed automatic transmission with steering wheel-mounted paddles.

Inside, standard equipment highlights include part electric seat adjustment, 6.5in colour display screen with iDrive controller, two-zone climate control and ISOFIX child seat attachments in the rear.