Vehicles with a 48 V on-board electrical system (EQ Boost technology):
ECO Assist analyses data for the vehicle's expected route. This allows the system to optimally adjust the driving style for the route ahead, save fuel and recuperate. If the system detects an event ahead, e. g. a speed limitation or a roundabout, it appears on the multifunction display 
. The following symbols can be displayed:
will appear around the symbol depending on the distance to the event ahead: few segments: the event ahead is near.
many segments: the event ahead is further away.
When the vehicle nears the event, ECO Assist calculates the optimal speed for maximum fuel economy and recuperative energy based on the distance, speed and downhill gradient. The Foot off the accelerator message will appear on the multifunction display. If the driver lifts off the accelerator pedal in good time, the remaining segments on the display will turn green until the event shown is reached. The drivetrain will be set for maximum fuel economy. The vehicle will coast, with the combustion engine switched off if necessary, and recuperate on its own using the electric motor. Recuperation will charge the battery.
If there is no response to the Foot off the accelerator prompt, the segments will remain white. The event will be shown for a short time after it has been passed.
If the event involves a vehicle ahead and when the coast-down recommendation is given, all segments will immediately turn green once there is a response to the Foot off the accelerator prompt.
For Active ECO Assist in drive program 
, symbol will appear on the multifunction display and on the head-up display beside transmission position 
. Symbol will also appear when the assistant display is not selected.
ECO Assist is active only in drive programs and 
.
ECO Assist can function more precisely if the route is maintained when route guidance is active. The basic function is also available without active route guidance. Not all information and traffic situations can be foreseen. The quality depends on the map data.
ECO Assist is only an aid. The driver is responsible for keeping a safe distance to the vehicle in front, for vehicle speed and for braking in good time. The driver must be ready to brake at all times irrespective of whether the system intervenes.
If there is poor visibility, e. g. due to insufficient illumination of the road, highly variable shade conditions, or due to rain, snow, fog or heavy spray.
If there is glare, e. g. from oncoming traffic, direct sunlight or reflections.
If there is dirt on the windscreen in the vicinity of the multifunction camera or the camera is misted up, damaged or obscured.
If the traffic signs are hard to detect, e. g. due to dirt or snow or insufficient lighting, or because they are covered.
If the information on the navigation system's digital map is incorrect or out of date.
If the signs are ambiguous, e. g. traffic signs on construction sites or in adjacent lanes.