BMW’S Mini brand has wound up the wick with two new John Cooper Works (JCW) models, offering higher levels of performance for both the second-generation hard-top and the new longer Clubman model.

This means 155kW of power and a 0-100km/h sprint claimed to be as low as 6.5 seconds – an improvement over the previous JCW kit for the Cooper S that realised 141kW/250Nm and enabled the small car to complete the 0-100 dash in 6.8 seconds.

John Cooper Works is a tuning house run by John’s son Mike Cooper, which built performance kits for the first- and second-generation BMW-built Mini that could be ordered as an accessory or fitted as an option at the factory.

The German manufacturer has now bought the JCW operation, bringing it in-house and creating a full model rather than an aftermarket-oriented special.

The latest iteration of the 1.6-litre direct-injection turbocharged engine generates 155kW at 6000rpm, up from 128kW in the regular Cooper S.

Torque is up from 240Nm to 260Nm from 1850rpm to 5600rpm. As is the case with the Cooper S, there is an overboost function that releases another 20Nm of torque for short periods.

The gain is achieved using fine-polished camshafts, a stronger cylinder head and valves, a new air intake, 0.4 bar more boost pressure and a free-flowing exhaust.

The result makes the JCW model – for the first time in second-generation guise – faster than the previous supercharged 1.6 (with a Chrysler-sourced engine), which completed the 0-100km/h benchmark in 6.6 seconds, a tenth outside this new model. Fuel consumption is rated at 6.9L/100km.

The new Clubman JCW model manages the 0-100km/h sprint in just 6.8 seconds and uses 7.0L/100km.

In order to withstand the extra torque over and above the standard Cooper S, Mini has fitted the JCW with a strengthened six-speed manual that uses closer gear ratios. No automatic transmission is available.

Other features include recalibrated sports suspension with firmer dampers and stronger anti-rollbars front and rear, which lowers the ride height by 10mm. More potent brakes are also onboard, with red-painted four-piston callipers up front.

As is the case with other Minis, the JCW cars use run-flat tyres. The wheels are no larger than the Cooper S, measuring 17 inches, but are a custom design made from lightweight aluminium.

As is the case with regular Minis, the JCW models come standard with electronic stability control, but they have an additional feature called Dynamic Traction Control, which allows the wheels to slip a little in the name of sportier driving.

Drivers can also completely switch off the stability control system.

In order to put as much of its power down to the ground as possible, the JCW models run what Mini refers to as an Electronic Differential Control Lock.

Rather than using a traditional mechanical system, this simply brakes the inside wheel. Mini claims this system enhances traction while limiting torque steer.

The exterior features that distinguish a JCW from a Cooper S are subtle, to say the least. Apart from the wheels and the red callipers there are some badges at the front and rear and slightly larger exhaust pipes (85mm).

As is the case with Chilli models, JCW cars come with bi-Xenon headlights, the option of bonnet stripes, leather/cloth combination seats, climate control, a premium sound system, dark rear windows, piano black interior and Anthracite roof lining.

The Clubman models also come with Bluetooth connectivity and a USB interface, an armrest and a removable false floor.

The JCW hard-top is priced at a hefty $8900 more than the standard Cooper S and $5300 more than the Cooper S Chilli. Choosing a JCW Clubman will cost $8100 more than the Cooper S model and $4300 more than the Cooper S Chilli.

As is the case with all Minis, there is a long options list, plus some exclusive JCW accessories including a large rear spoiler, more aggressive bumpers, sportier suspension, strut braces, perforated brake discs, carbon-fibre gearshift knob and gearshift lever surround, and a gearshift indicator light.