This Mercedes C180k Blue Efficiency heralds the brand’s belated entry into the eco-branding arena led by BMW‘s Efficient Dynamics.

This Blue Efficiency model replaces the standard, and big-selling, C180k entry car in all trim levels, which means the 19% and 11% improvements in CO2 and mpg respectively are available to all drivers.

The drop to 149g/km is achieved via a new smaller engine – that offers the same 156PS power – along with low rolling-resistance tyres, smaller door mirrors and changes to the engine management system. Mercedes has also fitted fuel economy and gear change indicators.

The downside is that BMW’s 143PS 318d model emits just 123g/km and Audi‘s 143PS A4 2.0 TDI 139g/km, leaving Mercedes several strides behind its key premium rivals.

Mercedes-Benz C180k Blue Efficiency
P11D price £22,858
Model price range £22,858-£50,432
Fuel consumption 44.8mpg
CO2 (tax) 149g/km/22%
BIK 20/40% per month £84/£168
Service interval n/a
Insurance group 13
Warranty 3yrs/unlimited mls
Boot space 475 litres
Engine size/power 1597cc/156PS
Top speed/0-62mph 143mph/9.5secs
On sale December 2008
Score 6/10
Verdict New C180K Blue Efficiency
is a good start but doesn’t
drag Mercedes into
low-CO2 contention yet