The John Cooper Works Cooper S (to give it its full name!) has had an interesting parentage. German owned, built in Oxford yet refined on the South coast to BMW’s exacting standards.

To the untrained eye the Works car looks pretty much unchanged from standard – just a set of unique, semi-circular Works badges which grace the front and rear bodywork. On closer inspection it sports twin chrome-tipped slash-cut Works embossed exhausts – again subtle. In fact the only part of the test car in questionable taste was the Aero body kit, but that’s an extra cost option. But the pretty cross-spoke R90 17-inch alloys most definitely were! Sadly there were no cars fitted with the optional JCW 18-inch alloy wheels, that look great in the pictures but I can’t help thinking how they would spoil the ride.

The changes are just as hard to spot under the bonnet; the only obvious way of telling a converted car is the silver-topped Works emblazoned cover to the intercooler. There’s also a special engine plate detailing the conversion number on the top of the rocker cover, much like the one fitted to my old classic Mini Cooper S.

Over 40 bhp up on standard yet the Works is still covered by the factory warranty and the TLC servicing (where applicable) remains intact. How many other 200 bhp S conversions boast that - peace of mind at a cost.

The interior too is standard S fare, with the same stylish dash and supportive sports seats. But Richard De Jong, General Manager at John Cooper Works was keen to show me the optional bespoke JCW sports seats. Manufactured by Sparco, the seats can be trimmed to match the rest of the interior. They look excellent quality and will probably add to the sporty feel of the Works.

It’s obviously in the driving where the differences between the Works and standard cars are most noticeable. The first audible change is the noise; it’s a much deeper mote with a pleasant metallic cackle on the overrun. Start off, and it’s soon clear that the Works car is far more capable than standard. This I believe can be attributed to the higher compression of the new cylinder head and the larger, more efficient Supercharger with increased boost.

The power is even more linear and accessible; it feels alert from as little as 1,500 revs right through to the red line. In short, it feels very capable in the lower and upper reaches of the rev band, where the standard car, feels restricted. I think it makes the standard car feel peaky and harder to drive fast. On another note, at speed the higher pitched whine of the new supercharger almost overrides the deeper exhaust note. Even more pleasing, is my problem with the change quality of the six-speed gearbox in the standard S, seemed less noticeable with the extra power.

Five minutes into my drive and we’re on the dual carriageway and I’m already breaking the speed limit! All with a cheeky grin from ear to ear. I defy any MINI owner not to be amused by the giant-killing performance; it’s really the car the standard S should have been. That’s the thing about this conversion, it may not be cheap at over £3,500 fitted, but every Works component is so well matched and balanced that the car feels factory standard. This where the long development time and meticulous BMW testing have come into there own.

The half-hour drive came to an end all too quickly, and I came to the conclusion that if I owned an S, I’d have to find the extra cash to splash on this kit. Residuals are likely to be even stronger too. I can’t see any owner losing money on a JCW converted car, you only have to look at the high prices commanded by converted classic Minis. Without doubt the best new MINI (in my view) is the official one, although I could be swayed. Hartge, Graham Goode anyone?

Review by: Martyn Collins AKA Ginger on the MINI2 forums.