Mini Cooper D driven

As part of the ongoing changes to the Mini range, theres now a new diesel engine in Cooper versions of the hatchback, Clubman and convertible.

Derived from the unit in parent company BMWs 1 Series, the turbocharged direct-injection 1.6-litre engine has more power and torque than the unit replaces, but is also more economical and has lower emissions.

At low speeds, theres no hiding the tell-tale sounds of a diesel engine, but once you pick up the pace, things quieten down nicely. The unit combines well with the standard stop-start system, too, although again theres no disguising the engines cough and splutter as it kicks back into life.

Petrol vs diesel

Generally, performance is strong, and the strong pull in the mid-range (much more than in the old engine) means you dont need to rev the unit as hard as you do with the petrol alternative.

That means the two engines have very different characters. The petrol model is the more exciting and sporty because it needs to be worked hard, whereas you can be a little lazier with the diesel, relying on its mid-range pull to haul you along at a perfectly acceptable rate.

The only problem comes if you let the revs drop much below 1750rpm. Amble round a tight turn in town in second gear, for example, and theres a distinct lull in proceedings until the turbocharger kicks the engine into life.

Coinciding with the introduction of this engine is what can only be described as a very minor facelift: revised bumpers at both ends, as well as a new black cross-piece below the front number plate and new-look rear lights.

That may sound like a lot, but even with the new and old cars side-by-side, youll be hard-pressed to spot the differences.

There are also new wheels and paint colours to choose from, revised trims inside, and some new options. These include adaptive headlights and Mini Connected, an in-car infotainment system that is controlled by Minis version of BMWs iDrive. It also works through an iPhone to give web radio, Facebook and Twitter updates, and a variety of other features.

The trouble is that these minor changes add up to a surprisingly major price rise. At £15,730, the new Cooper D hatchback, for example, is more than £500 dearer than the model it replaces and there are similar rises in the Clubman and Convertible ranges.

Perhaps more significantly, its also over £1000 more expensive than the petrol-engined Cooper, which has more character, is quicker to 60mph and still does over 50mpg. Unless you do an awful lot of miles, youll struggle to make up that kind of price difference in lower fuel bills.

What Car? says

Better than the old car, but we prefer the petrol model

Andy Pringle