Join Date: Mar 2012
Car: 2012 Subaru Outback 2.5i Limited
Ok, i found the answer. I am right afterall. Subiesailor, do you have a 4th gen OB?? You got it all wrong man.
The button to the left of the steering wheel turns OFF (and ON) VDC (vehicle dynamics control). This is stability control. According to Owner's Manual: "VDC helps prevent unstable vehicle motion such as skidding using control of the brakes and engine power."
Basically, if you press this button, then you have no stability control. BUT, you still have traction control to route power to the wheel with the most traction. Subiesailor got me all confused thinking that Subaru is crazy.
What i wrote above is true to Subaru and to every other SUVs that i have driven. Traction control on the OB is ALWAYS ON. You deactivate VDC to get rid of the dethrottling which will happen if you're buried in snow. VDC is what kills engine power and does all sorts of stuff to your brakes because it thinks that you're skidding. With it OFF, you still have traction control. And yes, traction control works by comparing speed differences b/w wheels on the SAME axle.
Now, traction control in itself can be a hindrance because it is a REactive system. One wheel has to spin faster than the other for it to intervene. Therefore, you may have lost momentum already before traction control kicks in. This is why pure off-roaders still prefer locker system, which is a proactive system.
And unlike a locker, traction control can only transfer a fraction of the power to the wheel that needs it the most...the rest is lost in heat dissipation from the ABS pulsating the brakes of the spinning wheel(s). This is why there is a limit as to how much power you have in going to the non-slip wheel(s) thru an obstacle or up an incline. Traction control only pulsates the slipping tire(s). In more off-road oriented vehicles (such as FJ Cruiser A-TRAC), the ABS can literally stop a spinning tire for a moment to send even more power to the wheel(s) with traction.