Has Audi made a perpetual motion machine?

Sunday, 2 September 2018

Audi seems to have created a perpetual motion machine. Well, sort of.

In a drive of the famous Pikes Peak hillclimb course in the Rocky Mountains, the maker's e-tron SUV-EV concept demonstrated remarkable ability to regenerate power downhill. On the 31km drive downhill from the summit, the pure-electric SUV recovered enough energy to drive the same distance again.

That's a remarkable achievement for an EV, although perhaps not quite as impressive as it sounds. The recovered energy is enough for another 31km, but not 31km back up the hill of course. And Audi fully acknowledges that the unique conditions, including a descent of 1900 metres, made the extreme energy-regeneration possible.

The e-tron SUV, which will soon go into production, has a system output of 300kW and can go from 0-100kmh in under six seconds. In the new WLTP test cycle, it covers more than 400km on one battery charge. 

**READ MORE:

* All about Audi's first all-electric vehicle

* Audi e-tron interior revealed

* Q7 e-tron will tow your three-tonne boat**

The recuperation system contributes to up to 30 per cent of the electric SUV's range. It involves both the two electric motors and the electrohydraulically integrated brake control system. For the first time, three different recuperation modes are combined: manual coasting recuperation using the shift paddles, automatic coasting recuperation via the predictive efficiency assist, and brake recuperation with smooth transition between electric and hydraulic deceleration.

Up to 0.3 g, the Audi e-tron prototype recuperates energy solely via the electric motors, without using the conventional brake – that covers over 90 percent of all decelerations.