A combine harvester (10), has driven wheels or tracks (14) for moving the combine harvester a system for detecting characteristics of crop plants (96) in front of the combine harvester and for calculating an expected mass throughput of the combine harvester from the detected physical characteristics an electronic control (80), configured to control the ground speed of the combine harvester to maintain a desired mass throughput of the combine harvester in consideration of the expected mass throughput of the combine harvester and a sensor (86) for detecting a combine harvester parameter that is indicative of an actual mass throughput of the combine harvester wherein the electronic control is configured to compare an output value of the sensor to a value indicating the expected mass throughput and to use a result of the comparison as feedback to control the speed of the combine harvester.
