The 'heart' of the MINI One D is a 1.4 litre, 4-cylinder diesel engine, developed in co-operation with Toyota Motor Corporation. During a two-year development period this engine was specially modified for use in MINI. The MINI One D engine produces 75bhp and maximum torque of 180Nm at just 2000rpm. This high-performance direct injection diesel engine combines second generation Common Rail technology with a turbocharger featuring an intercooler. To save weight the cylinder head and crankcase are made from aluminium giving the MINI One D an unladen weight of 1,175Kg.

Fuel consumption in the combined cycle averages 58.9 mpg, and on 50 litres of diesel the MINI One D has a range of up to 625 miles. This means that frugal minded drivers will be able to drive from the Isle of Skye to the Isle of Wight on just one tank of fuel. The CO2 emission figure of 129g/km, ensures that the MINI One D falls into the lowest company car tax bracket.

The six-speed manual transmission, which is fitted as standard on the MINI One D (and also the MINI Cooper S), has been specially adapted to the diesel engine's characteristics in order to make the most effective use of the car's power. The 0-62mph sprint is reached in 13.8 seconds, whilst in fourth gear 50 to 75 mph is achieved in just12.3 seconds. The sixth gear ratio has been reduced in order to lower the engine's speed and fuel consumption on long distance journeys.

The MINI One D has been differentiated from the MINI One by a MINI One D logo on the rear boot lid and MINI Cooper S side sills. In addition, the MINI One D has bigger front-end air intakes for extra engine cooling and a closed off rear bumper skirt concealing the exhaust pipe.