It averages 62.8mpg and emits less than 120g/km of CO2, improvements of 9.0mpg and 20g/km over the regular sDrive20d.
To make these possible, theres a new version of the 20ds 2.0-litre four-cylinder diesel engine; power falls by 14bhp to 161bhp, but you get an extra 22lb ft of torque.
A longer sixth gear means the engine is turning over at just 1700rpm at the UK motorway limit, too, while low-rolling-resistance tyres are fitted to lighter alloy wheels.
These features supplement the usual X1 economy aids: an engine stop-start system, brake energy recovery technology, active aerodynamics and a gearshift indicator.
Whats it like to drive?
Good in parts. Straight-line performance is excellent. With abundant torque, the engine is responsive, although its noisier than other four-cylinder BMW engines.
Do as the shift indicator advises and youll be making frequent use of the six-speed gearbox, particularly in urban traffic. Alas this highlights the cars clunky gearchange and offset pedals.
The X1 steers and handles well (the sDrive part of the name signifies rear-wheel drive, whereas xDrive models are four-wheel drive), but the low-speed ride can be a bit unsettled.
Wind and road noise are well controlled.
Whats it like inside?
Pedals apart, the X1 has a good driving position, with excellent all-round visibility.
While theres generous headroom front and back, rear legroom is limited and, with the transmission tunnel taking up space, the back seats are tight for three.
The boot is a reasonable size, and the rear seats fold down for more volume.
Surprisingly for a BMW, the cabin plastics feel rather hard and cheap. However, the dashboard is well laid out and the car is competitively equipped.
Should I buy one?
If youre in the market for a compact crossover with exceptional economy, this new Efficient Dynamics version of the X1 is worth a look. Given that its cleaner and more economical than the similarly equipped sDrive20d SE and costs 115 less, it makes excellent financial sense.
However, impressive though the figures are, the X1s quality and practicality disappoint. We prefer the all-round capabilities of the Audi Q3.
What Car? says