We tested the new gearbox in a Cooper D five-door hatchback.
The extra inertia of a diesel engine compared with a petrol means upshifts can only be made so quickly. In practice, then, and with the gearbox in manual and Sport mode selected, the new transmission doesn't seem to swap to a higher ratio any more urgently than the previous auto. In normal use, though, upshifts do feel appreciably sharper with a less pronounced torque interruption. Shifts are smooth and unflustered, too. Incidentally, Mini is not quoting comparative gearshift times for the two transmissions.
The new gearbox also offers more precise control over downshifts in manual mode, whereas the old automatic would occasionally ignore the driver’s input. Mini's engineers say they worked extremely hard to ensure the car’s low-speed comfort wasn’t adversely affected by the new transmission. In fact, they claim that in back-to-back tests, the DCT was smoother and more refined than the auto. Out on the road, you do sense the same busy, ever so slightly clunky downshifting that’s typical of twin-clutch transmissions when slowing to a halt, but it’s hardly enough to mark the new gearbox down.
In this application, the DCT will upshift in manual mode when the engine hits the limiter rather than holding the lower gear, but that will be revised when the gearbox is introduced to higher-performance models such as the Cooper S.
The omission of shift paddles on baseline models is a slightly contentious point, particularly on a car that trades on its sporty character. At least the gear selector operates in the ‘correct’ way in manual mode, which certainly isn’t a given; you push it forward to change down a gear and pull it back to shift up. It’s all about momentum; pushing the lever forward while hanging against your seatbelt under heavy braking is much more natural than pulling, and tugging the lever backward while being pinned to the seat back under acceleration - as much as a fluttery three-cylinder diesel can pin you into your seat, at least - is more natural, too.
Gearbox aside, the Mini Cooper D five-door is a very commendable, if slightly awkwardly styled, hatchback. Its interior feels decidedly premium, with high-grade materials and solid build quality, while the typically darty, agile driving dynamics we’ve come to expect of Minis are present and correct. The modest diesel engine, meanwhile, is burly enough to not feel overworked and it’s impressively refined, too. The distinctive three-cylinder diesel soundtrack, meanwhile, only becomes intrusive under very heavy load.