This includes adding the first ever three-cylinder petrol engine in the 1 Series. The new 1.5-litre 118i matches the 136hp of its 1.6-litre, four-cylinder predecessor, yet it consumes 5.0l/100km with CO2 emissions of 116g/km, compared to 5.4l/100km and 125g/km for the old engine.

With the eight-speed automatic gearbox, consumption decreases further, to 4.8l/100km with CO2 emissions of 112g/km.

Three-cylinder engine options are also widened for the 2 Series Gran Tourer seven-seat MPV. This includes a 102bhp 216i as the entry-point for the petrol range, while diesel options now start with the 95bhp 214d, which offers 3.9l/100k fuel consumption and CO2 emissions of 104g/km.

Elsewhere, four-cylinder engines have been upgraded throughout the range. BMW has upped the power of the 18d diesel to 150hp, available in the 2 Series Coupe and Convertible, 3 Series Gran Turismo and, for the first time, as an entry-level diesel in the 4 Series GranCoupe.

The 418d GranCoupe consumes 4.1l/100km with CO2 emissions of 107g/km for the automatic gearbox, or 109g/km for manual versions.

BMW’s ubiquitous 20d diesel engine, which was upgraded to 190hp last year, joins the 2 Series Gran Tourer range during the summer, while the 3 Series Gran Turismo and 4 Series Coupe will also benefit from the latest version.

There are also efficiency improvements for the 25d diesel. Fitted to the X5 SUV, this produces 228bhp, while fuel consumption has decreased from 5.3l/100km to 5.6l/100km in the new model, corresponding to a 10g/km reduction in CO2 emissions from 149g/km to 139g/km for the two-wheel drive X5 sDrive25d.  

Production begins this July, with pricing to be announced closer to the launch.