BMW 635d Sport

Five years after the engine’s launch, BMW has finally slotted its superb twin-turbo 3.0-litre diesel into the 6-Series coupé, creating the world’s first oil-burning luxury Grand Tourer.

BMW 635d Sport

Sport variant holds road particularly well. Integrated spoiler has been added to bootlid

Shifter is new

Cabin is beautifully built, but could do with more stowage space

Impressive diesel now offered in 6-Series

BMW 635d Sport boot

Rival: Mercedes CLS320 CDI
While it’s not strictly a two-door coupé, Mercedes’ ultra-stylish CLS is also available with a strong diesel. The 224bhp 3.0-litre V6 isn’t as powerful, clean (200g/km) or efficient (37.2mpg) as the BMW, but it is significantly cheaper, costing £43,957.