A method for estimating the performance potential of the primary power source of a hybrid vehicle

A method for estimating the performance potential of a primary power source (12) of a hybrid vehicle (10) comprising that a first display value is calculated, which is an estimate of the performance potential of the primary power source (12), wherein comprises calculating the difference between the value of a torque command and the value returned in response to the torque command torque delivered amount; a second display value is calculated based on several system dynamics equations, wherein said second display value is an estimate of the performance potential of the primary power source (12); and combining the first and second display value, in order to obtain an estimate of the performance potential of the primary power source (12).