Electric and hydraulic transmissions both offer power management, energy storage and flexibility. It is even possible to eliminate the mechanical drive train completely and have an in-wheel motor installed in the hub of each wheel.

These series systems are only feasible if all the transmission components have a high efficiency, also at part load and start up conditions. Furthermore the power density, especially for the wheel motors is a challenge.

Compared with electric series hybrids the Hydrid has an extreme high regenerative efficiency, more than double than that of electric hybrids. Furthermore challenges connected to hydraulic hybrids like weight, cost and packaging/NVH can now be met due to the new enabling floating cup technology.