Coasting function (Driving at idling speed)

The coasting function reduces the fuel consumption of cars with automatic transmissions.

The coasting function reduces fuel consumption in cars with automatic transmissions. The principle is simple: if the car is travelling on a flat or slightly downhill road and the driver takes his foot off the accelerator, the car will shift itself into neutral. This reduces mechanical resistance and therefore fuel consumption. As soon as the driver touches the brake or the accelerator, the corresponding gear is engaged again. For example, DSG automatic transmissions from the 4th generation onwards are equipped with the glide function.


Some hybrid and mild-hybrid cars can even switch off the combustion engine completely and drive using only the electric motor. When acceleration is required, the car can start the combustion engine again in a flash – BMW ActiveHybrid5, Porsche Panamera S Hybrid or Mercedes-Benz E 300 BlueTec.