Driven: BMW 6 Series Gran Coupe

BMW's equivalent of a CLS? A squished 5 Series? It's neither, says Riggers

BMW has come rather late to the four-door coupe scene. Arch-rival Mercedes virtually re-invented the genre back in 2004 with the CLS (we say re-invented because there have been four-door coupes of one sort or another pretty much since coupes have been around) and since then all sorts of manufacturers have joined in the fun. Now, as well as the CLS, we have the Passat CC, Audi getting in on the act with the A7 and A5 Sportback, and arguably even the Porsche Panamera and Aston Martin Rapide coming to play.

Longer wheelbase helps stability...

Better late than never
Now there's a four-door coupe with a double-kidney grille and a Hofmeister kink available in the form of the new BMW 6 Series Gran Coupe.

And how many better places are there to test a car with the 'proportions of a classic grand tourer coupe' (BMW's words, not ours - we'll let you make your own call on that) than Sicily, home to that legendary Italian road race, the Targa Florio?

Well, plenty actually. This is after all essentially an executive saloon, albeit one dressed in chinos, espadrilles and a casual shirt rather than a full business suit and so perhaps deserves a rather more real-world test situation. But the Gran Coupe does at least have aspirations towards the sort of bespoke luxury that would have caught the eye of Signor Vincenzo Florio when he inaugurated his eponymous Targa back 1906.

...as well as practicality

Especially in its comparative exclusivity (BMW UK foresees shifting just 700 Gran Coupes in its first full year, 300 fewer than the coupes it'll sell over the same period), so we'll forgive BMW for sending us to the sun-soaked Med instead of soggy Blighty to try the new 6 Series Gran Coupe (how generous of you, Riggers - Ed).

What about the car then?
But before the driving, a little about the car itself. Those familiar with the rest of the 6 Series range will find little to surprise them. The same options of a turbocharged six-cylinder petrol, twin-turbo diesel six and twin-turbo petrol V8 (which isn't due for a few months yet) are carried over from coupe and convertible, as is the welcome return for the driver-oriented dash, electric power steering, auto stop-start, adaptive drive and ZF eight-speed auto.

'Frozen Bronze' paint is light sensitive...

What is different, apart from an extra pair of doors, is an extra 113mm in the wheelbase. This gives the big 6er the space for rear-seat comfort, and adds only 70-90kg to the overall weight, depending on spec. It also has a striking effect on the car's dynamic behaviour, as we shall see later.

Similar, but not the same
It is also not simply a slinkily re-bodied 5 Series, though from the car's proportions it is tempting to imagine it as such. Sure, it shares much of its DNA with the 5er. In fact, its double wishbone front suspension and rear multi-link architecture is shared with the 5 Series, as are its basic drivetrains. Heck, the Gran Coupe, coupe and convertible 6 Series share the Dingolfing plant with the 5 and 7 Series, so there's more than a little family resemblance between them.

...but we reckon it can look good

The 6 Series Gran Coupe might find its closest relative in its two-door cousin, then, but the two cars are definitely distinct from one another.

BMW chassis man Jos van As is clear why: "The extra length comes from the wheelbase, and a longer wheelbase makes the car more stable. It also helps to push the weight balance to the rear of the car, shifting it by about one per cent and giving it a more even weight distribution. This is especially the case with the six-cylinder engines; less so the big V8."

Jos is right, too - the 6 Series Gran Coupe is more stable, more predictable and somehow a little bit more resolved than the regular coupe. But perhaps this is partly subjective; the extra patina of luxury and quality (and the Gran Coupe certainly seems brilliantly put together) perhaps means the 6 Series' penchant for cruising rather than hooning just gels better with the more relaxed MO of the four-door coupe than it does with the pointier sports coupe.

Toffee and vanilla trim an acquired taste...

Engine vroom
That twin-turbo diesel is still a stunner as well, a big 465lb ft slug of torque just shoving the Gran Coupe along at considerable velocity with little apparent effort. The 320hp of the petrol-powered 640i struggles a little more, with 'just' 332lb ft to call upon, but that does at least give you the opportunity to muck about with the manual mode on the excellent ZF gearbox - in the Diesel it's far better just to let it change gears at its own pace.

As we discovered when we drove the diesel in the two-door 6 Series, the 313hp turbo straight-six also imbues the Gran Coupe with an almost muscle car feel and - above the first few rpm at least - a curiously V8-alike soundtrack. An official combined mpg of 49.6 is just one reason why the bulk of Gran Coupes sold in the UK will be diesel powered but it is gratifying to know that it sounds ruddy great, too.

..one which Riggers has yet to get

That electric power steering is a bit of a party-pooper, however. Combined with the (optional) active steering on our test car, it manages the curious trick of feeling at once gloopy and hyper-reactive, rather tempering the ability of what is otherwise a faithful, predictable and entertaining chassis.

Hey there, big guy
It feels like a big car, too. Though this is a subjective issue - since you sit low, it's hard to get a sense for where the rounded edges of the Gran Coupe - the effect is undeniable. Despite the poise and balance of the big Bee-Em, it's actually quite difficult to place the car on the road, as you're always vaguely unsure of its exact proportions. This was exacerbated on our Sicilian test routes, with narrow, unforgiving country roads covered in a convenient sheen of sandy dust that reduced grip levels astoundingly - we doubt it would be so much of a problem on wider, more grippy routes.

The 6 Series Gran Coupe, then, is more dynamically capable, far more practical, and probably prettier than its two-door cousin. Which frankly makes it the pick of the 6 Series range and, costing only around £1,800 more than an equivalent coupe, makes it hard to understand why you might want the two-door...

BMW 640d GRAN COUPE
Engine:2,993cc 6-cyl, twin-turbo diesel
Transmission: 8-speed auto, rear-wheel drive
Power (hp):313@4,400rpm
Torque (lb ft):465@1,500-2,500rpm
0-62mph: 5.4 sec
Top speed: 155mph
Weight: 1,865kg
MPG: 49.6mpg
CO2: 149g/km
Price: £63,900

BMW 640i GRAN COUPE
Engine:2,979cc 6-cyl, turbocharged
Transmission: 8-speed auto, rear-wheel drive
Power (hp):320@5,800-6,000rpm
Torque (lb ft):332@1,300-4,500rpm
0-62mph: 5.4 sec
Top speed: 155mph
Weight: 1,825kg
MPG: 35.8mpg
CO2: 181g/km
Price: £61,390