Efficiency Assist
Efficiency Assist uses vehicle, route and traffic information to help the driver reduce energy consumption without transferring responsibility for speed or safety.
Sensors used
Efficiency assist can use forward Cameras for signs and road geometry, Radar for traffic ahead, and map, route, gradient and location data from Positioning and Vehicle Motion. The system combines these inputs to anticipate speed changes rather than reacting only after the driver reaches them.
Temporary signs, stale map data and incorrect lane association can produce poor advice. Sensor Fusion covers conflicting evidence, while Calibration, Cleaning and Sensor Health covers unavailable or degraded live sensors.
Information sources
A predictive system can combine:
- navigation geometry, gradients and speed limits;
- live traffic and known junctions;
- cameras reading signs or traffic ahead;
- radar measuring a slower lead vehicle;
- battery temperature, state of charge and power limits;
- the selected destination and charging plan.
The result may appear as a prompt to lift the accelerator, a recommended speed or automatic deceleration when adaptive cruise control is active.
Predictive coasting and regeneration
An EV can save energy by avoiding unnecessary acceleration and by timing deceleration so the vehicle reaches a lower-speed zone without heavy friction braking. The controller may choose coasting when momentum can be preserved or regeneration when speed must be reduced.
Maximum regeneration is not always the most efficient choice. Converting motion to electricity and back introduces losses, so avoiding the need to recover energy can be better than accelerating and then regenerating.
Integration with cruise control
When linked to adaptive cruise control, Efficiency Assist can reduce speed before a bend, junction, roundabout or lower limit, then return to the selected speed when appropriate. This is still longitudinal driver assistance. The driver must verify the limit, road condition and right of way.
An incorrect map limit or misread sign can cause unexpected acceleration or deceleration. The source of a speed change should be visible and easy to override.
EV range impact
Aerodynamic resistance rises rapidly with speed, making cruising speed especially important for highway energy use. Smooth acceleration, earlier deceleration and lower speed can extend range, but the benefit depends on vehicle efficiency, weather, elevation and traffic.
The feature cannot eliminate heating, cooling, tire or aerodynamic losses. A useful interface explains the reason for a recommendation rather than presenting a precise range gain that may not materialize.
What to compare
Evaluate the quality of map data, sign recognition, prompts, automatic speed adaptation and driver override. Also check whether the system supports the local road network and whether route planning preconditions the battery for charging, which serves charging performance rather than propulsion efficiency directly.