Roland Perry wrote:
In message
, at 03:39:08 on Mon, 27 Oct 2014, Recliner remarked:

ASC supersedes simple traction control, though it's sometimes called
traction control (that was the name used when I first got it, many years
ago, before the more sophisticated ASC superseded it). It reduces the
torque going to a wheel without traction,

It can only do that if the controlling element is in the differential.
Otherwise all the torque is still going to the wheel, but the brakes are
stopping the wheel from rotating too fast, which means those brakes are
absorbing the power, which is thus not (purposely it seems) available at the road surface.

All the torque that the available adhesion on each tyre can support is
independently monitored and delivered to each wheel. Trying to deliver any
more torque would cause the wheel to spin, thus reducing the power
transmitted. So, by absorbing some of the power in the brake, more can be
successfully transmitted through the wheel.

And the really good thing is that all this achieved with no extra hardware,
just clever electronics using the existing ABS system that all modern cars
have. So it doesn't increase the weight or mechanical complexity of the car
at all, and has an insignificant impact on costs of already highly
computerised modern cars.

So it's not only more effective than a locking or limited slip diff, but
also cheaper, simpler and lighter.