All three diesel engines available in the 1 Series hatchback use the same 2.0-litre common-rail unit found in other BMWs. The base 116d has 115bhp, the mid-range 118d has 143bhp and the range-topping 120d 181bhp.
Confusingly, the 125d also features a 2.0-litre powerplant, but of a newer design and shared with the X1. It produces 215bhp, 332lb ft and, when equipped with the eight-speed auto, a remarkable 126g/km of CO2 and 58.9mpg.Even the 120d offers more than adequate performance; with 280lb ft of torque from 1750rpm, 60mph comes up in around seven seconds.
With 280lb ft of torque from 1750rpm, performance from the 120d is as strong as you’d hope: 60mph comes up in around seven seconds. The powertrain’s all the more exceptional because, fitted with ZF’s excellent eight-speed automatic gearbox as an option and BMW’s Efficient Dynamics fuel-saving ancillaries as standard, the car emits less than 120g/km of CO2. This vehicle is capable of bettering both 140mph and 60mpg; not at the same time, of course, but remarkable from the same car.
The 143bhp 118d takes 8.9sec to cover 0-62mph whereas the 120d manages it in 7.2sec. Perhaps most impressive of all is the fact that the most powerful version of the engine emits only 2g/km more than the 118d’s 118g/km and is quoted as having the same 62.8mpg combined fuel consumption as the lower-powered car.