This gives a little explanation about how the Nissan GT-R's AWD system works. Very much like BMW's xDrive:
http://www.autoevolution.com/news/ni...ned-35006.html
And here's a little bit of info about how the 2016 Alpina B6 with xDrive bests the M6 with a combination of more power, torque and traction than the M6.
http://www.autoblog.com/2015/02/12/2...oupe-official/