BMW will be debuting the 2013 6 Series Gran Coupe, a four-door sibling of the popular 6 Series coupe. In fact, the Gran Coupe is just 4.4 inches longer, with its seat configuration stated as 4 plus 1. Under the hood, the sleek four door 640i will be fitted with the N55 3.0 liter inline six engine with turbo. On the other hand, expect the 650i to be fitted with xDrive all-wheel drive or the standard rear-wheel drive and a larger 4.4 liter twin turbo V8. Both versions will be equipped with an eight-speed automatic transmission. via: autoblog