The third generation MINI is still four months away from the showrooms but now we know what to expect. The newcomer is almost indistinguishable from the out-going six-year-old but it is extensively changed, writes Rob Golding.

It has a new platform, new engines, new transmission and every body-panel is new - even the (stiffer) roof. It has a new interior, new handling characteristics, new steering and new drive-by sound. In a faintly disguised form it was shown to a few journalists at the Zandvoort race circuit in Holland last week. Official Press photos will be available soon; then formal ride and drive for the motoring Press; then prices; then an on-sale date some time before Christmas.

The visual tease is almost too good a game to spoil, but here goes. From the front the clue is the headlamp treatment. Instead of being mounted in the bonnet, the lamps are now fixed to the body and show through cut-outs. The wheel arch protectors have also moved from the clamshell bonnet panel to the side-frame to save nudge damage to that complex bonnet pressing.

From the back there is a subtle change to the glass-to-metal join on the C-pillar. From the side, only the most perceptive eye can see that the car is the same height but 2cms taller at the waistline. There is a more muscular curve to the side and boot panels. That improves boot space a tad and extends overall length by 6cms.

The changes have been provoked by two necessities and two preferences: to raise the bonnet height which did not have enough crumple space above the engine; and to improve fuel consumption and emissions performance. The preferences were to accommodate the keen US market with a softer ride, and improve front-seat leg-room. Footwells are both deeper and wider. It is the bonnet height change (2cms taller at the trailing edge) that forced the higher waistline and therefore the shallower glasshouse that preserves the same overall height.

The overarching priority though, was to not change the distinctive profile which has been extraordinarily successful because of the echo of classic Mini's wheelhouse and separate bonnet. It is design that is poor aerodynamically and therefore costly on fuel consumption but considered a sacrifice worth making. The platform now has a full under-body shield to get some airflow efficiency back.

Out goes the unburstable Chrysler Tritec engine made in Brazil, and in comes the petrol unit designed jointly with PSA. It is made in France but the BMW version is assembled at Hams Hall near Birmingham. PSA could also become the provider of a diesel in place of Toyota who had the only offering that fits the current MINI engine bay.

The steering is now electric-assist and the transmission changes from CVT to six-speed auto (the same design as the Golf GTI box). The loss of the CVT transmission whine, together with the change from supercharger to turbo on the Cooper S, changes the drive-by note.

While the distinctive go-kart feel, tenacious grip and throttle steer are maintained or improved, the ride is softer and the cabin noise reduced. Both are deemed important virtues for the US market.

There are financial benefits in the changes for BMW. The car is easier to assemble than before and therefore cheaper. The whole of the front-end assembly is outsourced and delivered line-side. The JV 1600cc engine will have production volumes of a million and therefore reap scale benefit.

MINI now comes ahead of Honda, Vauxhall and Land-Rover in the rankings by size of UK car producers and is behind only Nissan and Toyota. Recent paint shop investment will allow a 40,000-unit increase on last year's 200,000-unit production. The first new derivative since the convertible - a modern interpretation of the Mini Traveller will emerge in 18 months.

Though the search for economies is never ending, the MINI business is a good one for BMW. The cost of manufacture in the UK is high but offset by the allure of a British product in the US and Japan. And the "build-your-own-car" on-line ordering process is so addictive that the average transaction price for a new MINI is now more than EUR20,000. The new, limited-edition BMW MCS JCW GP is not only the world's longest automotive acronym - deliberately unexplained for your greater amusement - but also an EUR50,000 MINI if garlanded with all the toys.

Rob Golding

See also: GERMANY: BMW reveals (some of) updated MINI

Note: Rob Golding has been the approved MINI biographer for 25 years. The latest of four editions - Mini Thirty-Five Years On - is now out of print. A new book covering all three generations of the brand will be published by MBI before Christmas.