Mini releases a Cooper with four real doors

Because Mini cars may be great but mini sales numbers are not, BMW’s smallest sub-brand is adding a new member to the family: the Cooper Four-door.

Mini announced Wednesday that it would officially be building its first true four-door Cooper, officially called the Mini Cooper Hardtop Four-door. Mechanically this hatchback is identical to the all-new Cooper that recently went on sale, with an extra set of doors squeezed in the back.

This means the base model will have a turbocharged, 1.5-liter inline three-cylinder engine with 134 horsepower and 162 pound-feet of torque. The awkwardly named S model (Cooper S Hardtop Four-Door) has the same drive train as the two-door iteration: a 2.0-liter turbocharged four-cylinder engine will make 189 horsepower and 207 pound-feet of torque.

Both versions will come standard with a six-speed manual transmission, while a six-speed automatic gearbox will be optional. This new generation of Minis ride on an all-new front-wheel-drive platform that BMW will eventually use in its own products in the U.S.

The wheelbase on the four-door Cooper is 2.9 inches longer than the two-door, while its overall length is up 6.3 inches. Inside, the growth continues: There’s an extra 0.5 inch of headroom, rear legroom grows 1.5 inches and there’s half a cubic foot of additional cargo space.

The rear seat will not fit three people, and splits and folds 60:40 for extra space.

Adding two doors will cost you just $1,000 on top of a base Cooper Hardtop. This means a starting price of $20,745 for this four-door model, square in the territory of a Volkswagen Golf, which is also new for 2015.

The move to four conventional doors on the Cooper is largely to make Mini’s cars more mainstream and therefore boost sales. Previously, Mini sold a four-door model called the Clubman, which featured a pair of small, rear-hinged doors behind the two main doors.

Although it was just as fun to drive as the Cooper, the Clubman was never a particular hit with consumers, selling a meager 5,200 copies in 2013. Mini debuted a concept version of a new Clubman with four traditional doors at the Geneva Motor Show in March. It’s expected to announce a production version of that model later this year.

The Mini Cooper Hardtop Four-door will dart into dealerships at the end of 2014.