Blue Efficiency is the name Mercedes gives to a wide range of measures it is introducing to cut the fuel consumption and CO2 of its cars.
To a large extent it had little option: the European Union has set major manufacturers an average CO2 target of 130g/km by 2012, with stiff fines if they fall short.
Mercedes' package is similar to the Efficient Dynamics system on BMWs, but goes even further. It includes new engines with stop/start systems, steps to reduce the amount of engine power needed to run ancillaries, fuel consumption indicators and gearshift advice lights, and measures to minimise aerodynamic drag and frictional losses from the tyres.
The E-Class is Mercedes' first range with four-cylinder, direct-injection, turbocharged engines 1.8-litre units that are being phased in to replace heavier, thirstier V6s. They power the E200 CGI and E250 CGI.
The E200 CGI will have a stop/start system from launch and all other manual four-cylinder models will get it soon afterwards.
Ancillaries driven off the engine, such as the air-conditioning, power steering and the fuel pump, have been re-engineered to minimise how much power they sap.
Aerodynamically, the new E-Class is said to better any other executive saloon. It has the same drag co-efficient (0.25) as the new eco-centric Toyota Prius, though because it has a larger frontal area it won't necessarily cut the air as cleanly.
The tyres play their part in saving fuel, too, cutting rolling resistance by a claimed 17% compared with those on today's E-Class.
Company car users will certainly notice the difference in their monthly tax bills the new E220 CDI sits six bands lower than the old model, while the E200 CGI reduces your liability by eight bands compared with the E200K but all owners should benefit at the pumps if they drive with a modicum of restraint.