Install various hydrotransformers on the Opel cars. All of them have marking at an end face which indicates compatibility of the transformer with the transmission of the same marking.

The hydrotransformer is located between the engine and the transmission, serves for torque transmission from the engine to a box by means of the hydrodynamic movement of a stream of working liquid. For this purpose the engine puts the oil pump of the hydrotransformer in action. The pump wheel which is at the same time a transformer casing will transform energy of the engine to kinetic energy of working liquid which influences a turbine wheel.

Pump and turbine wheels rotate with a different speed. Therefore, for example, at start-off from the place transformation coefficient very high then with increase in frequency of rotation of a turbine wheel it goes down. However even at big speeds there is certain "sliding" of liquid. Even with a high frequency of rotation of a bent shaft of the engine only 85% of torque are transferred to a shaft of a box. Therefore the engines completed with the automatic transmission spend slightly more fuel, than engines with a mechanical box. This defect is eliminated by means of the blocking coupling.