The invention relates to a method for operating a motor vehicle drive comprising at least one internal combusting engine (10), at least one electric machine (20) mechanically coupled to said internal combustion engine (10) and at least one power storage battery actively connectable to said electric machine (20) and to the internal combustion engine (1) in an on-board electric network, wherein said internal combustion engine (10) and electric machine (20) produces a nominal required drive torque (M) in a substantially common manner, the instant electromotive torque reserve (MEres) of the electric machines(s) (20) is determined and the internal combustion engine torque reserve is taken into account as a minimum reference torque reserve of the internal combustion engine for at least one or several internal combustion engines (10).