Quote:
Originally Posted by drob23
The affect of AWD, especially a reactive system like xdrive, will be pretty marginal compared to the timescales ESP is able to actuate at.
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It is not entirely correct to call the xDrive a "reactive" system. While the xDrive system reacts and redistributes power according to the information from the sensors and driver inputs, it is technically an active system.
This is how it is defined. With an active AWD system or any active differential, torque delivery can be varied at will usually via a computer controlled clutch. So, Haldex based VW/Audi will be considered as an active system. The new active rear diff in the F10 M5 and C7 Corvette are other examples.
The Torsen based VW/Audi system or other viscous coupling based systems on the other hand are considered as passive. Because there are no means to actively control torque distribution via computer programming. Power distribution is varied when wheel slippage occurs.
Of course with Audi you can also have a passive Torsen center diff coupled with an active rear diff.
While you go look for mentions of torque vectoring on the f30, check out this video on xDrive as well. Both the blonde and brunette cute.
http://www.bmwusa.com/Standard/Conte...ng/xDrive.aspx