"Less is more". This slogan certainly proves true when looking under the bonnet of the E-Class. That's because the newly developed and modified four-cylinder powerplants have a higher output than the previous six-cylinder units, despite the reduction in displacement. Plus they return impressive fuel-consumption figures that were previously only achievable in the compact-car class. The Mercedes strategy is to use turbocharged engines with lower displacement in place of high-displacement, non-turbocharged engines. Key benefits of the concept include lighter weight, reduced internal friction and a more economical fuel-consumption map. The new four-cylinder diesel engine in the E 250 CDI BlueEFFICIENCY model, for example, is proof that the plans have worked out successfully: with an output of 150 kW/204 hp, a peak torque of 500 Nm and a displacement of 2.1 litres, it develops around seven percent more power and delivers 25 percent more torque than the previous V6 diesel engine with a displacement of three litres whilst consuming around 23 percent less fuel: just 5.3 litres per 100 kilometres (NEDC combined figure), making it far more fuel-efficient than comparable saloons in this performance class. The CO2 emissions figure for the new four-cylinder diesel models is 139 grams per kilometre – up to 24 percent lower than the figures achieved by the previous CDI models.