ECO PRO Mode helps drivers reduce their fuel consumption by up to 20 percent, depending on their driving style – according to an internal BMW fuel consumption study. The additional functions, coasting (with automatic transmission only), Route-Ahead Assist and ECO PRO Route (both with Navigation System Professional only), deliver even more savings potential. The coasting function disconnects the drive train from the engine, causing the vehicle to ''coast'' without additional power input. This occurs as soon as the driver takes his or her foot off the accelerator between the speeds of 50 and 160 km/h without braking and the Route-Ahead Assist does not detect any change in the speed limit. Using data from the navigation system, the Route-Ahead Assist is able to recognise curves, built-up areas, speed limits and highway exits, and gives the driver tips to slow down in advance. Depending on your driving and the traffic and road conditions, the ECO PRO Route displays the most efficient route. The on-board computer shows what percentage of fuel can be saved by using the ECO PRO Route.