The 6 series includes a coupe and a convertible, both of which come factory standard with a V8 engine and offer optional all-wheel drive. The nice surprise, however, is the distinguished Gran Coupé 650i xDrive, a 4-door coupe equipped with a 445- hp engine. Like in most BMW series, an M version is offered for more performance-oriented drivers. With 560 horsepower, it can really put the wind in your hair!