The new BlueDIRECT V6 engine was developed using lightweight materials consistently. It features spray-guided direct petrol injection with piezo injectors, four valves per cylinder and adjustable intake and exhaust camshafts. In addition, the energy efficiency of its auxiliary assemblies has been enhanced. The CLS 350 BlueEFFICIENCY thus saves on fuel, reduces CO2 emissions and optimises running smoothness. With an output of 225 kW, its maximum torque of 370 Nm is available at an engine speed of 3500 rpm.

The CLS 350 BlueEFFICIENCY also features the ECO start/stop function which reduces the vehicle's fuel consumption and emission levels by switching off the engine when the vehicle is at a standstill or coasting to a stop. The new operating logic causes the engine to restart automatically as soon as the driver depresses the clutch pedal fully or steps on the accelerator.

(CLS 350 CDI BlueEFFICIENCY: fuel consumption combined: 6.8 –7.0 l/100 km, CO2 emissions combined: 159–164 g/km)[1]