MINI Australia has taken the next step in the continual expansion of its model range with the official launch of the Oxford-built Coupe and Roadster ‘twins’.

The addition of the new Coupe and Roadster bring the number of separate Mini bodystyles to six – joining the Hatch, Cabrio, Clubman and Countryman – compared to just a single model line only a decade ago.

Lower (by 21mm for the Roadster and 29mm for the Coupe) and 5mm longer than the hatch but sharing the same 2467mm wheelbase, both new models are positioned as more performance-oriented than their cosmetically similar siblings.

Both get a more sharply raked (by 13 degrees) windscreen than the hatch and hatch-based Cabrio, distinct ‘three-box’ bodyshell (a first for Mini), an active rear spoiler that automatically deploys above 80km/h and retracts again below 60km/h, plus – in the case of the Coupe – an integrated rear roof spoiler.

The Coupe features a – to put in diplomatically – polarising “helmet” roof design, while the Roadster gets stylish silver circular rollover bars and a standard wind deflector between the seats.

In what Mini claims to be a nod to simple British convertibles of yesteryear, the folding black soft-top on the Roadster is opened and closed manually with a roof latch – although a semi-automatic version is available as an option.

Each bodystyle is available in both entry-level Cooper S and hot John Cooper Works variations, with each powered by the same turbocharged 1.6-litre engine, though in different states of tune.

The Cooper S comes with a standard six-speed manual or an optional ($2350) six-speed automatic transmission with steering wheel paddle shifters, while the JCW is manual only.

The Cooper S has 135kW at 5500rpm and 240Nm of torque (from 1730-4500rpm), enough to sprint from 0-100km/h in 6.9 seconds for the Coupe (7.1s for the auto) and 7.0s for the soft-top (7.2s auto) on the way to a 230km/h top speed for the Coupe (227km/h for the Roadster).

Coupe fuel economy is rated at 6.3L/100km on the combined cycle (6.7 auto) and 6.4L/100km for the Roadster (6.8 auto).

The hotter JCW gets an extra 20kW (to 155kW) and 20Nm (to 260Nm), allowing the Coupe to dash from 0-100km/h in 6.4s and the Roadster in 6.5s, while top speed is 240km/h for the Coupe and 237km/h for the Roadster.

The JCW Coupe is said to be the fastest volume-produced Mini ever.

All models come with a speed-adjusting electro-mechanical power steering system, along with a standard Sport button that increases steering firmness and feel, and sharpens the throttle.

The Cooper S gets 294mm ventilated front discs and 259mm solid discs on the back, while the JCW gets 316mm units up front and 280mm at the rear.

Stability control, ABS brakes with electronic brakeforce distribution, cornering brake control, brake assist and hill-start assist are also standard, while the JCW gets dynamic traction control and integrated electronic diff lock control (which is optional on the Cooper S).

Passive safety equipment fitted as standard includes front airbags and head-thorax airbags, which are integrated into the sides of the seat backrests.

Suspension is by a single-joint MacPherson strut with anti-dive control up front and a multi-link rear axle with aluminium longitudinal struts.

With the rear parcel shelf removed, the Coupe’s 280-litre storage capacity is 20 litres greater than the stretched Clubman. The Roadster offers 240 litres of luggage space, which is unaffected by the fabric roof when it is retracted.

Both models get a ‘through load function’ that provides access to the boot from the cabin.

Standard equipment on Cooper S versions of both models includes automatic climate-control, bi-Xenon headlights, rear parking sensors, MP3 and auxiliary-compatible sound system, Bluetooth connectivity, cloth/leather seats and 17-inch alloy wheels.

The JCW adds run-flat tyres, an aero kit, 10-speaker Harmon Kardon sound system with USB, twin racing stripes, tinted headlights and sports suspension.

Mini, of course, provides a raft of options, including satellite-navigation, Recaro sports seats and model-specific sports stripes.

Nine exterior paint colours are available, while the Coupe has three available contrasting roof colours.

Mini Australia national manager Kai Bruesewitz told GoAuto the company expects to sell around 450 Coupe/Roadster models by year’s end, two-thirds of which will be the hardtop.