The general principles and strategies to control the work of switching devices in a step transmission of the car are considered. It is assumed that the synchronization of the rotation of the transmission elements during the change of gears is carried out with the active participation of the engine, without interrupting the flow of energy to the wheel engines and with accurate reproduction of an arbitrary program of car movement. For clarity, the study of control algorithms of the "engine - transmission" system is based on the analysis of the effectiveness of possible modes of clutches operation. However, in reality, it is a completely abstract process and it does not make sense to associate it with a specific technical embodiment. The measure of process efficiency is governed by energy consumption. It is taken into account that: 1) the process of shifting determines the modes of engine operation which is actively involved in the implementation of the shift, and this affects fuel consumption; 2) gear shifting and concomitant synchronization of rotational movements are always associated with the dissipation of energy in the form of heat.It was found that it is possible to objectively assess the effectiveness of the control of gear shifting processes if we consider them through the prism of optimal control of the overall system "engine - transmission". But it is easy to understand that the Zeroshift concept is by all indications the embodiment of a kind of "technical" compromise as opposed to various formal compromises. In this case, the process of actual gear change is reduced to almost an instantaneous act of gear change, which will significantly affect the principles of the general theory of "engine - transmission" system optimal control: the synthesis of control laws will be reduced to the construction of shift maps, but this will exacerbate the problem of so-called looping.