A method for starting a combustion engine of a vehicle powertrain during free-wheeling with engine off, the method being performed by a control device; the vehicle powertrain comprising: a combustion engine comprising an output shaft, a gearbox arranged to selectively transfer torque between the combustion engine and at least one driving wheel, the gearbox comprising an input shaft, and a clutch arranged between the combustion engine and the gearbox, the clutch connected to the input shaft of the gearbox and the output shaft of the combustion engine; the method comprising the steps of: - in response to an instruction for start of the combustion engine, controlling the clutch to a partially closed state so as to transfer torque from the input shaft of the gearbox to the combustion engine, thereby starting the combustion engine; - when the combustion engine has started, but prior to the output shaft of the combustion engine has reached a rotational speed synchronised with the rotational speed of the input shaft of the gearbox, controlling the clutch to an open state; - synchronising the speed of the combustion engine to the speed of the input shaft of the gearbox through control of fuel injection to the combustion engine, wherein the step of controlling the clutch to the open state is initiated in response to an indication that a predetermined condition for opening of the clutch is fulfilled, and characterized in that the predetermined condition for opening of the clutch is based on a prediction that the torque transferred to the combustion engine during opening of the clutch is sufficient for the combustion engine to reach a state at which it may be accelerated by control of fuel injection. the vehicle powertrain comprising: a combustion engine comprising an output shaft, a gearbox arranged to selectively transfer torque between the combustion engine and at least one driving wheel, the gearbox comprising an input shaft, and a clutch arranged between the combustion engine and the gearbox, the clutch connected to the input shaft of the gearbox and the output shaft of the combustion engine; a combustion engine comprising an output shaft, a gearbox arranged to selectively transfer torque between the combustion engine and at least one driving wheel, the gearbox comprising an input shaft, and a clutch arranged between the combustion engine and the gearbox, the clutch connected to the input shaft of the gearbox and the output shaft of the combustion engine; the method comprising the steps of: - in response to an instruction for start of the combustion engine, controlling the clutch to a partially closed state so as to transfer torque from the input shaft of the gearbox to the combustion engine, thereby starting the combustion engine; - when the combustion engine has started, but prior to the output shaft of the combustion engine has reached a rotational speed synchronised with the rotational speed of the input shaft of the gearbox, controlling the clutch to an open state; - synchronising the speed of the combustion engine to the speed of the input shaft of the gearbox through control of fuel injection to the combustion engine, - in response to an instruction for start of the combustion engine, controlling the clutch to a partially closed state so as to transfer torque from the input shaft of the gearbox to the combustion engine, thereby starting the combustion engine; - when the combustion engine has started, but prior to the output shaft of the combustion engine has reached a rotational speed synchronised with the rotational speed of the input shaft of the gearbox, controlling the clutch to an open state; - synchronising the speed of the combustion engine to the speed of the input shaft of the gearbox through control of fuel injection to the combustion engine, wherein the step of controlling the clutch to the open state is initiated in response to an indication that a predetermined condition for opening of the clutch is fulfilled, and characterized in that the predetermined condition for opening of the clutch is based on a prediction that the torque transferred to the combustion engine during opening of the clutch is sufficient for the combustion engine to reach a state at which it may be accelerated by control of fuel injection.