Improvements to a rolling start-stop system

An engine stop-start system of a vehicle, the system comprising a processor communicatively coupled to a plurality of vehicle sensors, each sensor of the plurality of sensors producing an output in response to a sensed parameter, wherein the processor is configured to receive 202 a plurality of sensor outputs from the plurality of vehicle sensors and determine 204 whether to start or stop an engine of the vehicle based on two or more of the sensor outputs, and wherein the plurality of vehicle sensors includes two or more sensors from the list comprising: a brake pedal angle sensor, a brake pedal switch, a brake pressure sensor, and an accelerometer. The processor may compare a first one of the outputs to a threshold that is a function of a second output, or second and third outputs, determining whether to start or stop the engine based on the comparison. A gradient of the road may be determined from the sensor outputs and used to vary a stop threshold (a brake pressure at which the engine is stopped). Also provided is a method 200 of operating such a system.