The first Mercedes Blue Efficency model will be launched by the end of the year when the German company’s answer to BMW‘s low-CO2 Efficient Dynamics technology hits the UK.

The biggest-selling C-class, the C180K petrol model, will be the first volume beneficiary. It arrives in January with a new 1.6-litre engine offering the same power as the 1.8 it replaces, but with a drop from 165 to 149g/km of CO2.

As well as the new engine, low rolling-resistance tyres and more aerodynamic wing mirrors, which will be introduced across the range, account for the reduction that also boosts economy from its current 40.9 to a claimed average 44.8mpg.

The A- and B-class are also benefiting from some Blue Efficiency measures, with the A/B150 and 170 models getting stop-start technology by the end of the year.

The firm also said that demand is outstripping supply for the Smart Microhybrid Drive available on 60 and 70PS versions of the car. The system works by running on electric power at very low speeds, which the company claims can cut fuel bills by 10% in cities.