REMEMBER the BMW 5 Series GT? Well, it has been replaced by the mighty 6 Series GT but, believe me, it's anything but a simple rebadging exercise.

The new model is 9cm longer, features the same wheelbase as the luxurious 7 Series, it has shed some weight and it's also been lowered to give the car a more dynamic sports coupe styling.

There's a choice of two diesels or two petrol engines and we opted for the 3.0-litre 265hp diesel version mated to an eight-speed automatic transmission with paddle shift.

This car started life costing £56,100, but after a raft of optional extras had been added, the cost had risen to £71,145.

When it comes to performance, the 630d can sprint from 0-62mph in 6.0 seconds, maxes out at 155mph and can deliver combined fuel economy of 47.9mpg with carbon emissions of 154g/km.

From any angle, the 6 Series looks imposing. It boasts a sloping roof, BMW's instantly recognisable kidney grille, a rippled bonnet housing the BMW badge, sweeping headlights, sunroof, M Sport aerodynamic body styling, twin tailpipes, privacy glass and plenty more besides.

Move inside and there is a modern, clutter-free feel to the car with a wealth of on-board technology to be explored. The power adjusted seats were upholstered in fine black Nappa leather with contrast stitching and piping - they even offer massage settings.

There is a 10.25-inch colour touchscreen along with the traditional BMW iDrive dial to access the many functions.

Creature comforts include an easy-to-programme sat nav system, a pitch perfect Harmon Kardon surround sound system, a head up display, full connectivity capabilities via Apple CarPlay or Android Auto and the ability to connect 10 devices to the car's Wi-Fi hotspot.

Back seat passengers can stretch out in comfort and have their own high standards of luxury too. Their seats can be tilted and heated and there are TV monitors fitted to the back of the front seats. There are even window blinds if a snooze is required.

When it comes to performance, the 630d is an accomplished all-rounder. It may not possess the same dynamic firepower as the latest 5 Series, but it's no slouch either. The acceleration through the automatic gearbox is very smooth and swift with the option of livening things up by flicking through the driving modes called Eco Pro, Comfort and Sport.

The car is beautifully composed and well balanced into corners. There is a little body sway if pushed really hard, but generally the 630d feels stable and well-planted.

The cabin is insulated against any road surface, wind or engine noise and even in busy town centres, the agility of the 6 Series GT belied its size, proving nice and easy to manoeuvre. The driver also benefits from excellent all-round visibility which is another plus factor.

The car cruises at motorway speeds and seems to glide across the Tarmac as the highly efficient adaptive suspension irons out the creases. And there is that added reassurance of xDrive all-wheel-drive should Mother Nature be having a particularly bad day.

When it comes to practicality, the 6 Series GT scores highly with an additional 110 litres capacity over the outgoing model. This is mainly due to the longer wheelbase and clever use of space. In fact, the boot capacity ranges from 610 to 1,800 litres with the 40:20:40 split-folding rear seats dropped flat.

The rear seats are lowered at the flick of a switch and the flat load sill makes transporting heavy or awkwardly shaped items much simpler. There are numerous practical storage options scattered throughout the car too.

And as one would expect, BMW has packed the car with a comprehensive range of safety features.