A controller for controlling an engine of a vehicle

A controller 125 for controlling a vehicle 103 engine 102, a control system 101 comprising a controller 125, a vehicle 103 and a method (200 Fig. 2), (500 Fig. 5). The controller is configured to cause stopping of power generation of the engine during movement of the vehicle in dependence on at least one criterion being met, e.g. vehicle speed or accelerator pedal below threshold or brake pressure above a threshold, and to cause restarting of power generation by the engine, in dependence of at least one input signal indicating a restart requirement for the engine to provide a power output. The control means is configured to receive a target engine speed value dependent on a current driveshaft speed and cause the engine speed to exceed and then fall to the target speed, during a period after receiving the at least one input signal and until a further signal is received indicating a reconnection of the engine to a driveshaft 104; the engine speed may then exceed the target engine speed.