[Tanoc]

Some cars are going with entirely electrically actuated brakes, either inboard on on-hub, compared to the E-Tron which uses traditional hydraulically actuated brakes. One uses an electric motor to wind something to tighten the spring clip by pulling it that then pushes the pads to the rotor and the other uses pressure to overcome the spring by pushing the spring to compress it and push the pads to the rotor. I'm guessing Audi didn't go with entirely electric brakes because they have a reputation for being harsh and difficult to modulate with the pedal, and Audi is supposed to be both a luxury and sport brand where pedal feel is important.

[whatevaa]

Are talking about brake-by-wire? Where brakes are controlled by electric only, and if electrics die, no brakes?

These are dangerous. Cars are not maintained to aircraft standards and will never be.

[Tanoc]

With electrically actuated brakes the default power off state is fully engaged. Meaning if the power dies the brakes lock up. That causes it's own issues, obviously, but a sudden deceleration is better than no deceleration at most road speeds.

edit: as formerlyproven below states, the ones currently for sale also have a hydraulic backup.

[dzhiurgis]

Insane take. They will be vastly more reliable than hydraulics.

[formerly_proven]

Brake by wire passenger car brake systems are still hydraulic... and all of them have a mechanical backup. There is not a single car on the market today using electromechanical brakes.

Unless you're talking about electric parking brakes in a thread about ABS.

[dzhiurgis]

Look up cybercab. Their new disassembled manufacturing method cannot support hydraulic lines.

[beAbU]

Just remember to pack a bottle of spare magic smoke incase something leaks!

[beAbU]

Which cars?