The Mercedes-Benz S 350 BlueTec will soon come with stop-start as standard, reducing overall fuel consumption to 6.2 litres/100km (45.5mpg).
Using Mercedes' ECO stop-start system, the diesel-engined S 350 switches off the engine automatically when the car comes to a halt. As soon as the driver releases the brake pedal, the engine restarts.
The other benefit of introducing this system to the S 350 BlueTec is a reduction in carbon dioxide emissions. Now, the S 350 emits 164g/km of CO2 - to the previous model's 177g/km - moving the car into Band D from Band E.
Mercedes says the S 350 BlueTec has also been helped by the introduction of twin-wire arc spraying technology for the engine. Previously used in the 6.2-litre V8 petrol engines of AMG models, it is now used in the diesel V6, saving 4.3kg on the engine's weight.
Prices for the Mercedes-Benz S 350 BlueTec with stop-start will be announced soon.