This can also happen when you drive on an open road and come close to the entrance of a city with a coresponding speed limit (GPS knows that) German example: 100 kph on the road outside of town, 50 inside the city.

The car will tell you beforehand to lift your foot off the accelerator, so you can decelerate to 50 by coasting and not using the brakes, therefore using less fuel and brake pads.

Source: I own a F21 1-Series that does the same. Source 2: I work at BMW where we develop driver assistance systems like these.

This can also happen when you drive on an open road and come close to the entrance of a city with a coresponding speed limit (GPS knows that) German example: 100 kph on the road outside of town, 50 inside the city.

The car will tell you beforehand to lift your foot off the accelerator, so you can decelerate to 50 by coasting and not using the brakes, therefore using less fuel and brake pads.

Source: I own a F21 1-Series that does the same. Source 2: I work at BMW where we develop driver assistance systems like these.