The present invention relates to a method for determining engine operation parameter values during and/or after a gear shift operation prior to performing said gear shift operation. The method comprises the steps of, prior to the gear shift operation: determining initial conditions comprising torque demand and engine speed and certain other engine operation parameter values; providing said initial conditions to an engine operation simulation model; providing a torque development course as well as an engine speed development course during the intended gear shift operation to said engine operation simulation model; and determining desired engine operation parameter values by means of said engine operation simulation model based upon the information thus provided to said engine operation simulation model.