We're now on the second generation of the Mercedes-Benz CLS, the luxury sedan that kicked off the whole "four-door coupe" craze. Since then, Volkswagen countered with the CC, Porsche launched the Panamera, and Audi won us over with its A7. So what about BMW? Now that the big 6 Series coupe has taken hold, the German automaker has added a proper back seat and two additional doors to create this, the 2013 6 Series Gran Coupe.
The first version of the Gran Coupe to arrive Stateside will be the 640i, powered by BMW's N55 3.0-liter turbocharged inline six, good for 315 horsepower and 330 pound-feet of torque in this application. Shortly thereafter, the 650i Gran Coupe will arrive, available with rear-wheel drive or xDrive all-wheel drive, boasting a twin-turbocharged 4.4-liter V8 tuned to 445 hp and 480 lb-ft. Both engines are paired with BMW's ZF-sourced eight-speed automatic transmission.
Compared to its two-door counterpart, the Gran Coupe is a full 4.4 inches longer, and most of that added length benefits the rear passengers. BMW's literature states that the stretched 6 Series has a 4+1 seating configuration, meaning there's actually a quasi-usable seat between the two outboard rear positions. (Good luck.) Judging from the photos, the Gran Coupe's interior is as luxuriously appointed and tech-laden as the rest of the 6 Series range – if not a little bit moreso.
We originally thought that BMW would debut the 2013 6 Series Gran Coupe at next month's Detroit Auto Show, but since the all-new 2012 3 Series is expected to make its public debut at Cobo Hall, we think BMW may hold off on the official Gran Coupe introduction until the Geneva Motor Show in March. We'll likely know official pricing details around that time, too. For now, soak it up in our high-res gallery and follow the jump to read the full details in BMW's press blast.