Dynamometer testing of a vehicle comprising, with only a first wheel shaft connected to a dynamometer test unit, including the steps of applying a first power to the first wheel shaft, determining a representation of the first power using the dynamometer test unit, determining a second power, different from the first power, being applied to one or both of the first wheel shaft and the second wheel shaft, the second power being a virtual power represented by a virtual representation of second power, and, based on the representation of the first power determined by the dynamometer test unit and the virtual representation of the second power, determining a first speed which is a representation of the speed of the vehicle driven on a road and subjected to the first and second power.