Road Test: Mini Hatchback 1.4 One D 3dr

I can almost hear the impatient rustle of Top Gear pages as I sit down to write this First Steer of the new &#163:11,390 Mini One D. It's a foregone conclusion, right? Hardly worth reading? Mini is brilliant, Mini gets diesel engine. Diesel engine is brilliant, both live happily ever after. The End.

OK, to be fair, that's not far off. I know it appears as if us journalists are party to some diabolical plot to rid the world of petrol engines and surround the planet in a fugue of black diesel smoke, like the evil 'Dr Polluter' in some environmentally-aware children's cartoon. But not every oil-burner is worthy of unilateral praise. Take VW's 1.9 PD engine, it may have enough stump-pulling torque to decimate a rainforest, but when under full throttle it's about as quiet as a Limp Bizkit gig.

Anyway, I digress. The first thing you need to know about the new Mini D's 1.4-litre engine is that it isn't a BMW unit at all. It's actually a modified version of the Yaris' common-rail D-4D, updated and adapted for the One by a contingent of Toyota and BMW engineers. I can see it now: animated discussions over sushi about 'vee' angles and shutline tolerance The addition of a second-generation Bosch injection system sees power 'jump' from 74 to 75bhp at 4,000rpm and, more significantly, torque has been increased to a useful 133lb ft at 2,000rpm.

First impressions are certainly good. No drumming your fingers on the wheel as you wait for the coil light to blink off - there isn't one - and the engine settles to a quiet, distant thrum at tickover. Things get even better when you drop your hand down to the gearknob and realise that there are six, not five, ratios to choose from. Choice of gearing can make or break a diesel car, and in this case the Munich firm has judged it to perfection. The Cooper S-sourced 'box's first five ratios are closely stacked for acceleration, with the sixth acting as an overdrive and helping the car attain its impressive combined fuel economy of 58.9mpg. The adoption of electronic 'drive-by-wire' technology means that throttle delay is also kept to a minimum, and the powerplant feels smooth and surprisingly eager to rev right up to its 5,000rpm limiter.

Now for the big question: to D, or not to D? It's certainly refined - quieter than the 1.6, in fact, when you're cruising at a leisurely 70mph - and has the measure of its petrol-powered counterpart in most situations performance-wise. Crucially, because the all-aluminium engine is so light (around 100kg), it hasn't blunted the Mini's hunger for corners either. But this isn't a 'performance' diesel engine in the vein of the Seat Ibiza's PD, lacking the necessary grunt to trouble the standard traction control even in the wet.

But you don't buy a Mini One for its ability to sprint to 60mph - if that was your main concern you'd rob your granny's pension and buy a Cooper. You buy a One because it makes you feel good, because it's now well built and comes with a fantastic five-year 'TLC' aftersales package. And with the new D, you'll buy it because it's the coolest small diesel car on the market. The End.

Euan Sey