Mercedes-Benz claims that its new S-Class hybrid will be the world's most economical gas-powered luxury car when it hits the market in 2009.

 

Based on the S 350 model, the new S 400 BlueHYBRID returns 6.6 L/100km on the combined cycle along with CO₂ emissions of 190g/km, figures that better even Merc's own diesel-fuelled S-Class models.

 

A 3.5-litre V6 engine combines with a 15kW electric motor for a maximum power output of 295bhp, while peak torque is rated at 284lb.ft. Thanks to the boosting effect of the electric motor from standstill, the S 400 hits 100 km/h in just 7.2 seconds.

 

The hybrid components are particularly well integrated into the S-Class, with the disc-shaped motor fitting into the torque converter housing between the engine and gearbox and the battery pack installed in the engine bay.

 

As the motor-generator also acts as an engine starter, the space formerly occupied by the traditional starting motor now accommodates the new current converter instead.

 

Mercedes has fitted a bespoke lithium-ion battery to store energy recovered from braking and to power the electric motor, which has allowed the fitment of a much smaller and lighter lead/acid battery in the trunk of the car.

 

At a standstill, the S 400's engine is usually switched off, though small electric motors ensure that the power steering and air conditioning can operate as normal and a digital display in the dashboard informs the driver of the status of the system.

 

The S 400 BlueHYBRID will go on sale in June 2009 in Europe, with China and the USA receiving the new car soon after.