For Audis of the future, energy conservation will play an increasingly important role, including in the car's suspension.

Audi is working on a prototype called "eROT," in which electromechanical rotary dampers replace the hydraulic dampers used today for an even more comfortable and fuel efficient driving experience.

The principle behind eROT is easily explained:

"Every pothole, every bump, every curve induces kinetic energy in the car. Today's dampers absorb this energy, which is then lost in the form of heat," said Dr.-Ing. Stefan Knirsch, Board Member for Technical Development at AUDI AG.

"With the new electromechanical damper system in the 48-volt electrical system, we put this energy to use. It also presents us and our customers with entirely new possibilities for adjusting the suspension."

As an actively controlled suspension, the eROT system easily adapts to uneven road surfaces and the motorist's own driving style. The new damper software increases the suspension functionality and eliminates the mutual dependence of the rebound and compression strokes that limits conventional hydraulic dampers.

Another advantage of the new damper system is its geometry. The horizontally arranged electric motors in the rear axle area replace the upright telescopic shock absorbers, which allows for additional space in the luggage compartment.

The eROT system also enables a second function besides the freely programmable damper characteristic: It can convert the kinetic energy created during compression and rebound into electricity. To do this, a lever arm absorbs the motion of the wheel carrier. The lever arm then transmits this force via a series of gears to an electric motor, which converts it into electricity.

The regeneration output is 100 to 150 watts on average during standard road testing  - from 3 watts on a newly built motorway to 613 watts on a rough secondary road. Under typical customer driving conditions, this equates to a CO2 savings of up to three grams per kilometre (4.8 g/mi).

Initial test results for the eROT technology are promising, suggesting we may soon see this new eROT system installed in Audi models of the future.

A prerequisite for this is the 48-volt electrical system, which is a central component of Audi's electrification strategy. In the next version planned for 2017, the 48-volt system will serve as the primary electrical system in a new Audi model and feed a high-performance mild hybrid drive, offering potential fuel savings of up to 0.7 litres per 100 kilometres.