The S 400 BlueHYBRID, due to arrive in the summer of 2009, is Mercedes-Benz’s first hybrid-drive passenger car. The combination of a modified V6 petrol engine and compact hybrid module should catapult Mercedes-Benz into the rarefied world of economical luxury saloons.

Combined fuel consumption is just 35.8mpg, resulting in the world's lowest CO2 emissions in the segment: just 190g/km. The 3.5-litre petrol engine develops 275bhp, while the electric motor generates 20bhp and a starting torque of 160Nm. The result is a combined output of 295bhp and a combined maximum torque of 385Nm.

The compact hybrid module is a disc-shaped electric motor that also acts as a starter and generator. The system offers a double benefit, as it both helps to save fuel and increases – says Mercedes – the driving enjoyment. This is partly due to the booster effect of the electric motor, as it backs up the petrol engine with a maximum additional torque of 160Nm during the high-consumption acceleration phase. The driver benefits from the combined action of these two units in the form of even more impressive torque characteristics and smooth, powerful acceleration.

The new S 400 BlueHYBRID , based on the S 350 but with an extensively modified drive train, is the first series-production model to be equipped with Mercedes’ efficient lithium-ion battery, specially developed for automotive use. It serves not only as energy storage for the electric motor, but also provides a 12V supply for such standard fittings as the headlights and comfort features.

Performance is, as you’d expect from Mercedes, impressive. The S 400 BlueHYBRID accelerates from 0-62mph in 7.2 seconds and reaches an electronically governed top speed of 155mph.

Text: Classic Driver
Photos: Mercedes-Benz