In this mode, the gearbox is by default in «D', but if there's a need for extra acceleration or a need to overtake, you can always just touch the lever and it will go into «S» mode. (carwale.com)
They are seamless and smooth in normal driving, and when you need extra acceleration, as for passing, the engine revs up and there is more noise, but their are no jerks, lurches, or anything else but smooth power delivery. (autoline.tv)
All Mercedes E-Class Saloon models include a nine - speed automatic gearbox and changes gear with a fluid and consistent response and acts immediately when extra acceleration occurs. (holmesautogroup.com)