The speed preset in DISTRONIC is predictively reduced according to the route ahead of bends, junctions, roundabouts or toll booths, then increased back up. If the route has been selected using the navigation system, the S‑Class also responds accordingly: if the car is in the slow lane, it is decelerated when approaching the desired motorway exit. The same applies to junctions where the navigation route prescribes a turn-off or ahead of which the driver activates the turn indicator.
The reduction in speed is in varying degrees, depending on the selected transmission mode (ECO, COMFORT or SPORT). In ECO mode, the cornering speed is configured to harmonise with Steering Assist. This means that automated driving for longer periods is also a reality on country roads. On highways and motorways, Active Distance Assist DISTRONIC controls the distance from the vehicle ahead within a speed range from 0 to 210 km/h, and keeps the car on track. One special feature: at speeds of less than 130 km/h, the steering assistant also works with road markings that are difficult to see.
Coasting characteristics, e.g. on downhill slops, can now also be taken into account. In the interests of smooth and efficient driving, the speed is reduced in good time. If the vehicle is equipped with a drive system suitable for "gliding" (coasting with the engine off), this mode is automatically activated when the ECO transmission mode is active.