# System Overview – SSP 259 EPHS – Electrically Powered Hydraulic Steering

> Schematic diagram of the EPHS and its advantages: energy savings of up to 85 % and about 0.2 l/100 km less fuel.

- Web page: https://catalog.polo.blue/self-study/ssp-259-electro-hydraulic-power-steering/system-overview/
- Original document (PDF): https://cdn.polo.blue/files/ssp-259-electro-hydraulic-power-steering.pdf

## System overview – schematic diagram

![System overview – schematic diagram (259\_006)](https://catalog.polo.blue/instructions/ssp-259/bb0643b64457e5cf.webp)

## Advantages of the EPHS – Electrically Powered Hydraulic Steering

![Advantages of the EPHS – Electrically Powered Hydraulic Steering (259\_007)](https://catalog.polo.blue/instructions/ssp-259/fb0945f93b1ef1cb.webp)

In comparison to the traditional, conventional power-assisted steering system the newly developed EPHS Electrically Powered Hydraulic Steering offers a multitude of advantages:

- Energy savings of as much as 85 %
- More environmentally friendly system as a result of lower energy demand and reduced energy use, as well as smaller quantity of fluid in hydraulic system.
- Taking realistic driving cycles as a comparison, fuel savings of about 0.2 l/100 km are achievable.
- Improvement in active safety as the steering is easy to operate when parking, but is firm at high speeds.

When driving solely on motorways, there is a high power loss at the bypass valve in a conventional power-assisted steering system as a result of the high engine speed, in other words at low steering angle rates and high engine speed, the power steering pump supplies an excess volume flow.

The new electrically powered hydraulic steering achieves its maximum economy from the low steering angle rate when driving on motorways and from the volume flow which is matched to the vehicle speed.

Even when driving in towns, the savings are still clearly perceptible (refer also to chart).