BMW will expand the 6 Series lineup -- which, until now, has consisted only of two-door models -- in 2013 with a new sedan.
Despite the name, the Gran Coupe has four doors and is technically a sedan. No matter -- the Gran Coupe's sultry looks and low, sloping roofline instantly distinguish it from a traditional sedan design. Aside from the revised sheetmetal and the addition of two doors, the new model is essentially a close twin of the 6 Series coupe and convertible models that are already on sale.
The Gran Coupe is marginally bigger than those siblings models, with its wheelbase stretched 4.5 inches and body stretched 4.4 inches compared to the 6 Series coupe. Interestingly, the Gran Coupe is longer (by 4.0 inches) and wider (by 1.3 inches) than a BMW 5 Series sedan., which shares much of the same mechanical architecture. Although the increased dimensions allows for a little more interior room, trunk space (16.2 cubic feet) isn't any greater than that of the coupe.
The Gran Coupe's front fascia design those used on existing 6 Series variants. The rounded nose features traditional kidney-shaped grilles and upswept headlights, with two long creases along the hood that meet at the Roundel emblem just above the grille. Xenon headlights are standard, although LED units are optional. In profile, the 6 Series resembles other so-called four-door coupes like the Volkswagen CC and Mercedes-Benz CLS-Class.

A sharp crease runs from the front fender emblem through the door handles, terminating at the edge of the LED taillights. The trunk is concave, with a flatter deck lid than the coupe and convertible models. The relatively short rear window is topped by a line of red LEDs, which serve as the high-mounted brake lamp. Eighteen-inch wheels, LED fog lights, and twin chrome exhaust tips are standard design flourishes. The C-pillars, of course, exhibit BMW's traditional Hofmeister kink.

Inside, too, the Gran Coupe doesn't fall far from the 6 Series tree. A tall center console bisects the cabin, while a 10.2-inch LCD screen for the iDrive system sits above the climate and audio controls on the center stack. Elegantly sweeping dashboard lines and BMW's traditional four-binnacle instrument cluster are present, with the same assortment of technology and equipment as other 6 Series models. In addition to iDrive, the Gran Coupe has the Driving Experience Control button, which allows the driver to alter an array of vehicle settings in presets called Comfort, Sport, and Eco Pro.
The increased vehicle length and wheelbase helps improve rear-seat legroom compared to two-door 6 Series models, and the headliner is scalloped above the rear seats to provide slightly more headroom. BMW calls the car a "4+1", a tacit admission that while there are five seatbelts, the Gran Coupe is really meant for four passengers; a fifth occupant would have to straddle the large center console.

Although the BMW Individual program lets buyers select nearly any interior design they desire, the company has crafted one special interior scheme that is exclusive to the Gran Coupe. Opal White leather is is used on the seats and door inserts, while Amaro Brown leather adorns the dashboard, consoles, headliner, and most other interior surfaces.
The Gran Coupe shares almost all of its mechanical components with the 6 Series coupe and convertible, starting with its choice of two engines. The 640i employs a turbocharged 3.0-liter inline-six rated for 315 hp and 330 lb-ft of torque, which can be had only with rear-wheel drive. BMW says the car can reach 62 mph in 5.4 seconds. Meanwhile, the 650i uses a version of BMW's twin-turbo 4.4-liter V-8 engine -- upgraded with Valvetronic variable valve timing -produces 445 hp and 480 lb-ft, gains of 45 hp and 30 lb-ft over the same engine in other 6 Series variants. BMW says the rear-wheel-drive 650i will sprint to 62 mph in 4.6 seconds, while the all-wheel-drive 650i xDrive will do the deed in 4.5 seconds. Both engines are mated to an eight-speed automatic transmission.

BMW hasn't yet revealed fuel-economy figures, but there's no reason to suspect they will differ much from those of the coupe: 21/31 mpg (city/highway) for the 640i, and 15/23 mpg for the rear-wheel-drive 650i. Engine stop-start is standard on both models.
As in the two-door versions, much of the suspension is made from lightweight aluminum, and adaptive dampers are standard. Optional chassis tech includes Active Roll Stabilization, which adjusts the anti-roll bars to keep the car level in turns; and Integral Active Steering, which varies the steering ratio and can also steer the rear wheels to help reduce the car's turning radius.
Safety gizmos range from stability control and parking sensors, to the 360-degree Top View Camera and blind-spot warning system. Other options include a Bang & Olufsen stereo said to provide "a feast of aural pleasure," Night Vision, and full-LED headlights. The M Sport package bundles new fascias and side skirts, black-chrome exhaust tips, black brake calipers, 19-inch wheels (with 20-inchers optional), leather and Alcantara seats, and a leather steering wheel.

Pricing for the car and its assorted options won't be revealed until closer to the on-sale date. Expect it to start slightly higher than the 640i coupe's entry price of $74,425 (including an $875 destination charge).
The 6 Series Gran Coupe will be unveiled at the Geneva Motor Show in March 2012, before making its stateside debut at the New York auto show in April. The 640i model goes on sale in early summer 2012, with the 650i models following later in the summer. Like other versions of the 6 Series, the Gran Coupe will be produced at BMW's Dingolfing, Germany, plant alongside the 5 and 7 Series.