A method for running a vehicle (100) that includes a combustion engine (101) which can selectively be connected to a driveshaft (104, 105) to deliver driving force to the driveshaft (104, 105) for propulsion of the vehicle (100). When the vehicle (100) is in motion, determining whether the vehicle (100) is approaching a downgrade and, when it is approaching the downgrade, disconnecting the engine (101) from the driveshaft (104, 105) before the vehicle (100) reaches the downgrade. Also a system and a vehicle are disclosed.