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The electric motors that push the pad onto the disc can also pull the pads away. Using a torque sensor, they can switch between pushing and pulling at an extremely high frequency, both controlling the braking force and keeping the wheels from locking up. This also means there’s no need for a conventional anti-lock braking system.

With each brake unit operating independently of the others, it also means the electronic stability control can be much more finely tuned.

An industry source said, “We recently ran a test involving two Audi A6 prototypes. One was fitted with conventional disc brakes, the other with the latest development of wedge brakes. In exercises that involved the cars braking from 62mph, the prototype with the wedge brakes regularly required less than half the distance to come to a complete standstill than the prototype with the standard brakes. The difference is nothing short of amazing.”

As well as providing greatly improved braking ability, wedge brakes are also significantly lighter than today’s most advanced hydraulic units, leading to a crucial reduction in unsprung weight – the key to improved handling and added agility.

They are also claimed to be more reliable, with longer service intervals due to the fact that they have fewer moving parts.

According to Autocar sources, the first car with wedge brakes is planned for launch by the end of the decade (probably from a big-name German maker), and a formal announcement will be coming soon, says Siemens.

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