Outstanding engines and a polished driving experience are both becoming givens where BMWs are concerned and the 6-Series doesn't break from this. You've got to like the styling to spend £50,000 on one but if you do, it's an excellent package that's part performance sportscar, part luxury grand tourer. The 6 is even reasonably affordable to run thanks to BMW's EfficentDynamics technology.

The days of BMWs that challenge and dumfound with their unorthodox styling appear to be at an end, at least for the time being. The Bavarians have stuck with the edgy design direction that emerged in production on the 2002 7-Series and was incrementally watered down to become something highly palatable on the 3-Series Coupe. Even the most ardent doubters have begun to backtrack where designer Chris Bangle's controversial vision is concerned so it seems that BMW's future will hold more of the same styling-wise with the real innovation happening beneath the surface. Say hello to the latest facelifted 6-Series.

Now that the formula has been tweaked and moulded into a winning one, why change it? There will still be the stalwart E39 5-Series owners who obstinately refuse to consider another BMW until all trace of Bangle's confounded 'flame surfacing' has been extinguished from its bodywork but it's clear with hindsight that things had to move on. BMW is used to getting things right and stuck to its guns while the furore stirred up by the 2002 7-Seiries steadily subsided with each new model launch. Today, some of the products are starting to be critically acclaimed for their styling as well as for their engines and dynamics. Most of the people who said it would never work are starting to gaze sorrowfully down at a big plate loaded with their words.

The BMW engine range is to the car enthusiast what an unguarded sausage factory is to a hungry Bavarian. Each possibility seems more enticing than the next and the 6-Series gets three of the juiciest specimens. The entry-point is the 3.0-litre high precision injection double-VANOS unit in the 630i. With 272bhp, it packs a hefty wallop but it can't match the low-end punch of the 3.0-litre twin-turbo diesel in the 635d. Diesel engines don't traditionally sit well in luxury coupes but this isn't a traditional diesel. It's slightly slower on the 0-60mph measure than the 630i but the engine's crushing peak torque of 580Nm is served up from just 1,750rpm, making it devastatingly fast in real world conditions. The 635d's surging acceleration has more in common with that of the range-topping 650i and its 4.8-litre unit but with 367bhp on tap, the V8 will retain an edge on the open road. Ring its neck and a supercar-esque 5.1-second 0-60mph sprint can be extracted. It would bludgeon through the 155mph barrier too, if the artificial limiter were not on guard. BMW are offering a sports package to all coupes in the 6-series range aimed at enhancing driving dynamics and adding a more sporting appearance.

"Whatever your viewpoint on the styling, the 6-Series remains an engineering master class."

The 6-Series manages to tread the fine line between proper focused sportscars and luxury grand tourers. Benign in traffic and silky on the motorway, it's comfortable during everyday driving but will devour immense distances at the drop of a hat. When you feel like using its formidable performance, the weighted-up steering and vast reserves of grip egg you on to push harder while the substantial size of the 6 melts away, leaving you with the impression of a vehicle far lighter and nimbler. The petrol models get a six-speed manual as standard but the 635d receives an advanced 6-speed auto with a beefed-up torque converter to manage its hulking biceps.

This is the facelifted 6-Series but you'd really have to eyeball one parked alongside the original car to pinpoint the changes. For the record, the headlamps have the LED technology that is so popular amongst the premium marques at the moment. It takes the form of a thin row of lights above the main projectors. More obvious is the redesigned front valance that accommodates differently shaped air intakes and at the back the bumper has been tweaked it increase the impression of width. Other than that, the grille is fractionally larger and the rear light clusters have been tweaked. The 6-Series remains an acquired taste and many will find it lacking in the classical beauty that's important in a £50,000 coupe but the lines are strong and purposeful in a manner that demands respect.

The interior lays on generous space for two with lots of adjustment in both the wheel and pedals so all shapes and sizes will fit. The rear seats are just for bags or kids. Build quality is superb, the design clinical and efficient, if a missing something in character. The minimalist feel is embodied by the iDrive control wheel the operation of which, to the uninitiated, remains like doing the Rubiks cube with a knife and fork. On the latest models, programmable 'Favourite' buttons appear on the centre console so that key functions can be accessed at a push rather than a four twirls, three jerks and a prod.

The 6-Series kicks off at £49,795 for the 630i with the 635d commanding a £54,450 sticker and the 650i yours for £56,550. Those prices are for the standard coupe but you can upgrade to Sport trim for £2,200 and the convertible models come in at approximately £5,500 more.

The introduction of a diesel engine on this 6-Series is an interesting development. BMW is fast building a reputation as the most environmentally-friendly of the prestige brands and that's a title that will be increasingly coveted as awareness of green issues grows. Others will follow suit but where will Jaguar or Maserati get an oil-burner to challenge the one in the 635d? Mercedes or Audi will find things easier in this respect but none of their current models directly challenges the 6. In the end, they may think it best to let Munich have the diesel premium diesel coupe segment to itself. As for this BMW's petrol engines, they're no slouches when it comes to economy and emissions themselves.

The latest 6-Series features BMW's EfficentDynamics technology across its engine range. While other manufacturers have focused their green efforts on headline-grabbing Hybrids and alternative fueling technologies, BMW developed a collection of small measures that together have a major impact on efficiency in its conventional engines. In the 6-Series, this EfficentDynamics package includes Brake Energy Regeneration, which uses energy recovered under braking to recharge the car's battery, an air-conditioning compressor that can be decoupled from the drivetrain to reduce engine drag and active flaps behind the grille that actually close off to improve aerodynamics. The 6 is a high performance sportscar but the 635d manages to return over 40mpg with 183g/km of CO2 emissions. Remarkable stuff.

The petrol contingent also performs strongly from an environmental and running costs perspective. You'll get 35.8mpg from the 630i and this is improved slightly if you specify the automatic gearbox. The 650i does just over 24mpg on the combined cycle so it's no eco-warrior but that's still admirable for a car with this much engine. Emissions for the 630i and 650i coupes are just 188g/km and 279g/km respectively.

Whatever your viewpoint on the styling, the 6-Series remains an engineering master class. The latest facelifted car sticks resolutely to the controversial BMW design direction that's becoming less so with each model launch but significant innovations beneath the skin render it even more competitive. The EfficentDynamics technology means consumption and emissions are now class leading while all the engines remain outstanding in terms of power and performance. The inclusion of active head restraints and some simplification of the iDrive control system will be welcomed by buyers.

Is the 6-Series a performance sports car or a luxury grand tourer? The truth is that it fills both roles admirably to the extent that rival products may do better to align themselves with whichever category the BMW isn't in. Sportscar purists who yearn for character and beauty won't find it here but sheer jaw-dropping competence? The 6-Series has it by the truck load.

TOP 5 6 SERIES DEALS

The results below show the top 6 SERIES deals on buyacar

	BMW 6 Series 635d Sport 2dr Auto Coupe
	ETR	Mthly	Saving £9,020	Price £46,425
	BMW 6 Series 635d 2dr Auto Coupe
	ETR	Mthly	Saving £4,899	Price £48,391
	BMW 6 Series 650i Sport 2dr Auto Convertible
	ETR	Mthly £1,255	Saving £9,862	Price £54,238
	BMW 6 Series 635d Sport 2dr Auto Convertible
	ETR	Mthly	Saving £9,578	Price £51,492
	BMW 6 Series 630i Edition Sport 2dr [272] Spec edn Coupe
	ETR	Mthly	Saving £8,702	Price £43,608

typical 11.82% APR

PCP finance quote over 48 months,  10,000 miles pa,  deposit of £1000