What is it?
The less expensive diesel version found in the third-generation Mini line-up. Up front there’s a 1.5 litre, 3-cylinder diesel engine, the same that can be found in the more powerful and costly Cooper D.
It features common-rail direct injection and a "TwinPower" turbocharger that, in this case, means a variable geometry turbine.
Differences to the more powerful Cooper D variant can only be found inside the engine’s electronic management system, so the One D’s hardware is exactly the same.
The ECU decreases power from 114bhp to 94bhp and maximum torque from 199lb ft to 162lb ft. Fuel economy also improves, from a claimed average of 80.7 mpg to 83.1 mpg.
The One D’s basic list price is also £1560 cheaper than the Cooper D, but it still costs £1140 more than the entry level petrol version, the 1.2-litre Mini One.
What's it like?
As is usually the norm with press cars, our test vehicle was laden with optional items – but looking beyond that, for a moment, there is no sign that this is an entry level variant.
Cabin quality is the same as in more expensive Minis, with a strong sense of robustness and a solid feel to most of the materials used inside, with just the right amount of soft-touch plastics.
The centre console keeps the oval display from the previous model, even if the speedometer is no longer there. The driving position is near perfect, lower than in most superminis and with an almost vertical steering wheel.
The 6-speed manual gearbox sampled here has a nice mechanical feeling and pedals have the right weight. The diesel engine is very refined; you really need to step outside the car to hear to the typical clatter.
There are no vibrations coming from the three pot, either, unless you push it all the way to the redline, which is missing the point in a car like this.
Make no mistake, though, this is still very much a Mini in the sense that dynamically it is always ready to play. Ask it to turn sharply and it will obey with gusto.