Engine and gearbox
The engine is a 2-litre four-cylinder turbocharged unit with 228bhp and 236lb ft of torque. It's closely related to the motor in the Cooper S, but boasts some significant internal changes in order to bring about the extra power. Lower compression pistons in the JCW’s engine means that the turbo’s boost has been increased, consequently upping the power. The turbo has also been relocated to reduce the distance the exhaust gases need to travel in an attempt to quicken response and deliver power across a wider rev range.
The engine isn’t the most characterful of units, but the tweaks do mean that it’s certainly effective. The most noticeable change is that maximum torque is delivered at 1250rpm, which means the JCW pulls hard from a near-standstill. The full 228bhp arrives later, at 5200rpm.
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The JCW is available with a choice of either manual or automatic gearboxes. The six-speed manual is your best bet, as it suits the car’s character better, the short, slick throw pairing well with the JCW’s handling characteristics. The manual gearbox also features an automatic rev-match function – which oddly only comes into play when in Sport mode – and this might not be to everyone’s taste but can serve a purpose during fast driving or can be disabled by turning off the traction control entirely.
Where the pre-facelift version of the JCW used a six-speed torque-converter gearbox the latest incarnation has an eight-speed Steptronic auto and it’s quick enough both going up and down the ’box. As is the fashion now, upshifts cause the JCW to emit a little burp from its exhaust on full-bore changes. It comes as standard with shift paddles on either side of the wheel to make the auto ’box a little bit more engaging.