With its new 4-series Gran Coupé, BMW aims to offer a more dynamic, elegant and sophisticated alternative to the 4-series coupé und convertible. And the Gran Coupé has exactly the same length, width and wheelbase as BMW's two-door coupé. But BMW is convinced this is a niche with a future. We checked out the Gran Coupé with a 180 kilowatt 428i gasoline-powered engine.