Which means it looks pretty much the same – albeit a bit bigger in the face department – but sits on an all-new platform with lots of shiny new tech on board.
First up, there's no escaping the fact the third-gen Mini isn't especially... mini any more. Of course it's vastly bigger than the 1959 original, but also 98mm longer, 44mm wider and 7mm taller than the outgoing Mini. It sits on a 28mm longer wheelbase, with wider tracks front and rear.
So the footprint's larger, but the engines are smaller. The MkIII Mini will be available with three-cylinder engines for the first time, and launches with three brand-new engines from BMW's EfficientDynamics engine family.
This three-pot 1.5-litre engine in the Cooper gets 134bhp, and joins a 1.5-litre three-cylinder diesel producing 114bhp in the Cooper D, and a 2-litre four-pot petrol with 189bhp in the Cooper S on the car's launch.
BMW says fuel consumption and emissions have been reduced by up to 27% compared to the outgoing engines, promising a combined rating of over 80mpg and just 92g/km of CO2 from the Cooper D. Which is impressive.
All three engines will come with a six-speed manual as standard, with a six-speed auto optional across the range. A paddle-shifting “sports automatic” transmission will be available, too.
We're told the suspension has been upgraded, improving further the Mini's annoyingly addictive “go-kart” feel. The front axle gets aluminium swivel bearings and steel axle supports and wishbones, while the expensive multilink setup at the back gets even more steel. There's the option of damper control with two setups (sport and comfort).
Inside as well as out, the new Mini is very much a case of evolution, not revolution. That willfully obtuse circular central “speedometer” remains, but doesn't actually show your speed any more – it's a display-screen only. There's the option of a pop-up head-up display and adaptive cruise control, plus an on-board SIM card that will automatically phone the emergency services in the event of an accident.
Of course, this being a Mini means you can personalise it to your heart's content. We're promised new “decorative trims for roof, exterior mirrors, bonnet, seat upholstery and interior surfaces”. Option wisely, buyer.
If you can avoid getting too ticky with the extras, prices start at £15,300 for the Cooper, rising to £18,650 for the Cooper S. That's a jump of a few hundred pounds over the outgoing model, but BMW points out you get a bunch more kit – onboard computer, front foglights, Bluetooth and more – thrown in for free.
The MkIII Mini will be built at BMW's Oxford plant. Its new “UKL” platform will also underpin the next-gen Clubman and Countryman, along with a five-door Mini hatch and BMW's upcoming 2 Series Active Tourer mini-MPV.
And, of course, the usual array of hot 'n' torque-steery John Cooper Works variants. But the debate for now, we suspect, may be dominated by the new Mini's new face. Lantern-jawed and muscular, or a bit... shocked?
A version of this story originally appeared on TopGear.com.