open differential question

[jleinaweaver]

my understanding is the V6 A6 version has an open differential, meaning the wheel that's spinning on ice just keeps spinning and the wheel on bare pavement will just sit there.

Thinking about this, what exactly is the advantage of an open differential? Is there advantages in cornering since the outside wheel might get a little more push? Does GM do this as a cost savings measure (a LSD being a little more expensive)? Trying to understand what the advantage is.

Also, what exactly does traction control do, specifically when you have an open differential?

[Robert91RS]

An open diff keeps the rear end of your car from sliding out from behind you when your driving on slick surfaces. The wheel that isn't spinning free keeps tracking straight. Traction control just reduces the throttle position and/or applys a small amount of brake to the spinning wheel depending on what the other sensors read.

[RickyTheStorm]

All I know is, at the track, both wheels have smoke rolling out of them - and that is all that matters to me