Mercedes-Benz to market S 400 BlueHYBRID next year

At constant speeds the intelligent electronics recognise situations such as relaxed motorway stretches, and automatically adjust the load point of the internal combustion engine to achieve a lower specific fuel consumption, thereby helping to save fuel and reduce emissions.

When rolling to a stop the recuperation function is activated as soon as the drive is interrupted in any way (foot off the accelerator, engine braking). Once the vehicle speed falls below 15 km/h, the petrol engine is automatically switched off.

If the driver brakes using the brake pedal, the electric motor initially begins to convert the vehicle's kinetic energy into electrical energy. In this case the electric motor acts as a generator, storing the kinetic energy as electrical energy in the lithium-ion battery. This process feels like a stronger engine braking effect to the driver. The conventional disc brakes at the wheels are not yet employed, saving wear and tear. The disc brakes are only activated if the driver applies heavy pressure to the brake pedal, braking the car together with the engine brake and recuperation.

Once the driver selects "R" (reverse) in the 7G-TRONIC automatic transmission when manoeuvring, this automatically activates the Manoeuvring mode and prevents the start/stop function from switching off the engine at short, frequent intervals.

The advantages of the hybrid drive system really come into their own in city traffic, with frequent stops at red traffic lights. Already switching off the petrol engine as the car frequently coasts to a stop significantly lowers the fuel consumption and emissions, while the long recuperation phases increase the battery charge. The electric motor ensures particularly comfortable and rapid restarting when the start/stop function is active.

On rural roads there are frequent changes between boost, constant speed and recuperation phases. Depending on the nature of the route, large quantities of recuperation energy are available to reduce fuel consumption and emissions. The more braking and acceleration phases there are, the better: uphill and downhill gradients, as well as winding, dynamic stretches, make for the largest savings.

The hybrid effect is inherently less important on motorways, however thanks to specific modifications to the V6 petrol engine and the 7G-TRONIC automatic transmission, the driver is also able to achieve significant fuel savings and correspondingly lower emissions on fast road stretches like these.

The S 400 BlueHYBRID is produced at the Sindelfingen plant, together with the other S-Class models. The petrol engine, 7G-TRONIC automatic transmission and electric motor are first put together to form a hybrid module, then delivered to the production line as a unit. The market launch in western Europe is planned for June 2009; China is expected to follow in August 2009 and the USA in September 2009.

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