Abstract: Methods for determining the height, horizontal position, and lateral position of the centre of gravity of a vehicle are disclosed. The methods comprise constructing a plurality of models of vehicle behaviour, each model including a plurality of parameters that determine vehicle behaviour including parameters that define the position of the centre of gravity. The method then measures actual vehicle behaviour during operation of the vehicle. The actual behaviour and the behaviour predicted by the models are then compared to determine which of the models most effectively predicts behaviour of the vehicle. The model that is most effective in predicting the actual behaviour of the vehicle is then assumed to include amongst its parameters an estimate of the position of the centre of gravity of the vehicle.