BMW will introduce a new mild-hybrid diesel engine in the 320d, reducing its CO2 emissions from 110g/km to 105g/km (NEDC correlated).
The powertrain is already fitted in the 520d, where it delivers a reduction in CO2 output from 117 to 108g/km and improves fuel efficiency from 53.3 to 56.5mpg.
Using a 48v starter generator, the system provides an 11PS boost to peak power and enables extended engine-off coasting.
It will be fitted as standard to all 320d models from April, as well as the X3 xDrive20d and X4 xDrive20d.
The engine is RDE2 compliant and therefore avoids the 4% diesel surcharge for company car tax.
Fleet News contacted BMW and asked for the WLTP emissions figures, which will be used for tax purposes from April this year, but were told they will not be published until March.
From Spring, BMW says it will have 33 additional variants that achieve RDE2 compliance (Euro 6d).
The car maker will also add an RDE2 compliant 2.0-litre diesel engine to the 1 Series, developing 190PS and emitting from 112g/km or CO2, in the Spring.