The 114d returns 65.7mpg with CO2 emissions of 112g/km in UK-market specification and is likely to have a starting price of under £19,000 for the three-door version.

Although the 114d will become the least powerful member of the 1 Series family, it is geared towards a low entry price rather than raising the bar for efficiency. It features some of the fuel-saving technology of the 116d EfficientDynamics, but not the longer gear ratios or revised engine mapping needed to undercut the more powerful car’s 99g/km CO2 emissions.

Instead, with a predicted entry price of £19,000 for the five-door, the 114d seems pitched at providing BMW with a rival to the £18,760 Mercedes-Benz A160 CDI BlueEFFICIENCY Avantgarde SE.

But, unlike Mercedes-Benz, BMW will not be bringing its most stripped down specification to the UK. Most of Europe will be able to order the 114d with steel wheels, matching the A-Class’s Classic SE spec and bringing fuel consumption down to 68.9mpg with CO2 emissions of 109g/km. All UK cars will be sold with alloy wheels.

Production of the 114d begins in November, and BMW said it has no plans to offer an EfficientDynamics version of the new model. Pricing will be announced closer to its UK launch, with the first UK cars likely to reach showrooms in January.

Also new to the BMW range is the 320i EfficientDynamics, which returns 53.3mpg and emits 124g/km CO2 from its 168bhp 1.6-litre petrol engine. At £25,730 on the road, the carmaker’s most efficient petrol 3 Series is £2,350 cheaper than the equivalent 320d EfficientDynamics.