There is something just wrong about a big coupe. Its decadence is at odds with the increasingly socially conscious world we live in. And yet we all go weak in the knees when we see a well executed two door that just drips with the right amount of purposeful style and outright performance.

With the four door 6 Series Gran Coupe, BMW is pouring all those ingredients into one product. That sentence should raise our collective eyes as it generally leads to something that tries so hard at everything and succeeds at nothing. Yet, as I sit here after spending a day with the 6GC touring the central California coast, I ‘m finding it hard to think of anything the car isn ‘t wildly successful at.

Forget for a moment that the 6 Series Gran Coupe isn ‘t a new idea. Mercedes, Audi and Porsche have all created their versions of the four-door coupe before it. And forget that this isn ‘t BMW ‘s first attempt to make a four door coupe (the ill-fated CS Concept was cancelled almost four years before). None of it matters because the 6 Series Gran Coupe is perhaps the best expression of the concept ever produced by a major auto manufacturer. From almost every angle inside and out, the car wears a confident style that is immediately likable – an elusive trait in more than a few modern BMWs.

Stylistically it straddles the line between four door sedan and coupe effortlessly. More than the competition, the 6GC seduces with a raked form while adding just enough voluptuousness around the wheels to give it an elegant yet purposeful look.

And that ‘s before you get in. Because once you do you ‘re again overwhelmed with styling statements that come from a place BMW rarely treads. There ‘s authority in the design and quality to the execution that finally surpasses Audi ‘s best in form and function. The 4+1 layout (essentially a four seater with an extra spot for someone who wants to sit with their legs crossed under them) extends the coupe metaphore visually with it ‘s elongated center console.

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The design is impressive but it ‘s the material quality that really wins you over. The BMW Individual leather (a $5,000 option or part of the $8,300 Individual package) is simply the best leather I ‘ve ever seen in a BMW. There is no faux leather pattern printed on it. Only contours and shape that come from nature. And don ‘t expect leatherette on the sides of the seats (a disturbing new practice BMW borrowed from Audi). Everything in the cabin is either leather, wood, glass or a premium pastic when you order the car with extended leather. Even the contrast stitching (the same as seen on all other 6ers) impresses with it ‘s laser like precision.

BMW stretched the wheelbase and overall length of the car 4.5 ” and 4.4 ” respectively. They then stretched the already sloping roofline to further accommodate rear passengers. But don ‘t let the full size rear doors fool you. This is not comfortable transportation for four across hundreds of miles. The angle of the rear seat cushions don ‘t allow for a truly comfortable seating position and the cocoon-like shape of the rear keeps things tight. Yes, it ‘s great space for 30 minute trips but full-size adults may struggle to find comfort after that.

This is not a car you buy to transport lots of people and things and BMW is obviously not trying to make that point or target that market. This is a car that an empty nester or executive will buy instead of an E Class, 5 Series or even X6. Or perhaps they ‘ll choose the 6er GC instead of the 911 because they may someday need those extra doors and seats. Either way they ‘re getting a slice of utility with a healthy dose of style.

The 640i GranCoupe we tested retails for $76,895 while it ‘s larger engined sibling goes out the door at $87,395. The 650i is also available with xDrive $90,395 (all including the $895 shipping fee).

The 650i also will help usher in BMW ‘s latest version of it ‘s 4.4L twin turbo V8. Power is up 45hp and 30 lb ft. Both cars include BMW ‘s updated auto start/stop system. 0-60 should be around 4.5 seconds – around .8 quicker than the 640i ‘s official 5.4 time. However keep in mind that number is straight for BMW – a company notorious for conservative times.

It ‘s also worth nothing that BMWNA will not offer the 6GC with anything other than BMW ‘s exceptional 8 speed automatic at launch. However, don ‘t be surprisedif a six-speed manual eventually shows-up on the order sheet.

While we didn ‘t drive the 650i in GC form we did drive the Coupe and Convertible last year over some of these same roads. And as much as we love power here at BF, it ‘s hard to argue with the 640i ‘s 315hp N55 twin-charged inline six. The 640i is hands down a better blend of performance and effeciency. It ‘s also lighter and a little more eager to change direction.

The 6 Series Gran Coupe is beautiful inside and out. Perhaps more so then any other BMW four door ever made. But BMW has built their reputation on how its cars felt and performed. Does the 6GC live up to that tradition?

It depends on what tradition you ‘re expecting. Does it feel as tossable and nimble as a 3er? With well over 4,000 lbs to lug around it decidedly does not. Does it follow the long and storied tradition of the 6 Series? Here the answer is a resounding yes. The 640i model we tested felt vault-like on the highway and eager to eat-up endless miles. Yet it was light on its feet when pushed and even had hints of oversteer while attacking the beautiful canyon roads of central California.

In fact driving the M6 Convertible back to back with the 6GC gave us a surprisingly high opinion of the latter ‘s chasis set-up. The 6GC clearly couldn ‘t compete on power delivery or brakes but the suspension set-up and relatively neutral handling didn ‘t feel starkly at odds with the much more focused M6.

No, it ‘s not at home at the track like an M car but like a few of BMW ‘s recent products (the 3 Series and rest of the 6 Series range come to mind) this is a car that the designers and engineers clearly got right. From first impressions inside and out to putting 200 miles on the car through some of the best roads central California has to offer, it ‘s a thoroughly impressive car. It ‘s a GT in the truest 2012 sense. It has an ability to cruise at high rates of speed for hours at a time without fatiguing the driver in the least (as evidenced by a 136 mph ticket a fellow journalist recieved during the press launch). Yet, despite the size, weight and four doors it also exhibits a surprsing neutral feel when driven with urgency.

Perhaps more than any large car BMW has ever produced, the 640i Gran Coupe is a winning blend of the best of modern BMWs with jaw-dropping good looks and performance that approaches levels a large GT car shouldn ‘t.

In this modern world of 4,000 sedans (4,191 for the 6GC) BMW has produced a sports sedan that embodies the GT class of cars from a bygone era and infuses it with modern technology and elegance that is almost beyond reproach.

The CLS, A7 and Panamera may have created the four door coupe market, but the 6 Series Gran Coupe just redefined it. While it ‘s not be the fastest, most spacious or the original, it may just be the best.