Next year, BMW will bring to market the 2013 BMW 6 Series Gran Coupe, but in the mean time, a test mule was spotted in Germany during the daily testing sessions.

Graduating from a concept level, the new 6er Gran Coupe is a four-dour coupe that uses the same ‘backbone’ platform that underpins the current 5-series, 7-series and 5 GT. The car will offer the same mix of six- and eight-cylinder petrol and diesel engines as those cars, and an eight-speed automatic gearbox.

The BMW Gran Coupe is labeled as a 4-door coupe type of vehicle with a distinctive sporty character. The Gran Coupe has been designed to combine the abilities of a GT and a sports car. The roof is 100mm lower than the 7 Series models, and its rear quarters slightly more restricted.

The car sits on the 5 Series platform rather than the new 6er. The wheelbase measures 116.8 inch and sits on a 74.9 inch wide track. To increase its sportiness, BMW engineers lowered the car by 3.5 inches when compared to the 5 Series sedan (54 inches). At 197.1 inches overall, the 6 Series Gran Coupe is 2 inches longer than a Mercedes CLS-Class.

The 2013 BMW 6 Series Gran Coupe carries the essence of brand values and the genes of BMW design into the future and the expectations are that these styling cues will turn up all over BMW range in the next few years. The sleek Gran Coupe retain iconic elements like the kidney-grille, Hofmeister kink and a less pronounced shark nose.

Powertrain options are expected to be the same as the 6 Series lineup: a 3.0 liter twin-scroll turbo with and the 4.4 liter twin-turbo V8. .

To keep weight off, the four-door uses aluminum for the front hood and doors, thermoplastics for the front fenders, and SMC plastic for the trunk lid. As with other top-line BMWs, a full suite of telematics and driver assistance systems are on the menu.

BMW Gran Coupe will go head-to-head with the Audi Sportback Concept (the future Audi A7), the Mercedes Benz CLS and the controversial Porsche Panamera.