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I've never had a vehicle with stability control before and I notice there is a button below the side mirror adjustments that allows you to turn it off. I'm wondering under what circumstances you would want to do that. I get the impression that the stability control might get confused or mess things up when you are say....climbing a hill under poor traction....say snow or ice. Is this when you would turn it off? Would you start to lose grip if you left it on then?
 

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If you ever get stuck where you need to "rock" the vehicle back and fourth, that's the time to turn it off.
 

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A professional driver on a slalom course or race track would also want to turn it off. Stability control systems have a tendency to be intrusive, often slowing the vehicle before it's absolutely necessary. Toyota's are famous for this, but I think the Subie's is a little less intrusive than most. I think I have felt the inside rear brake slowing me a bit on some hard turns I've played with.
 

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Tup said:
I've never had a vehicle with stability control before and I notice there is a button below the side mirror adjustments that allows you to turn it off. I'm wondering under what circumstances you would want to do that. I get the impression that the stability control might get confused or mess things up when you are say....climbing a hill under poor traction....say snow or ice. Is this when you would turn it off? Would you start to lose grip if you left it on then?
I leave mine on at all times, I only turn it off when I wanna have some fun, or when I need to rock the vehicle, or need wheel spin cause these eagles STINK... I've set off VDC many times, even on dry surfaces... When spring comes round, my baby will get a new pair of shoes. CAN'T WAIT
 

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The Eagles do Suck!

They were good for the first few thousand miles in the snow, now they are not soo. Going to get some Michelin snows for next winter... I have the X-Ice on my CRV and they are awesome, but they dont make a size for the beca. I will look into one of the Alpin's.
 

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I still dont see why its necessary to turn off VDC when there is a need to rock the vehicle. Can someone enlighten here?
 

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njjuliano said:
I still dont see why its necessary to turn off VDC when there is a need to rock the vehicle. Can someone enlighten here?
If you are actually "stuck" in the snow, VDC also turns on/off the traction control. Therefore if VDC (stability control) is still on...the traction control won't allow you to spin the tires when your trying to free yourself.
 

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snork said:
If you are actually "stuck" in the snow, VDC also turns on/off the traction control. Therefore if VDC (stability control) is still on...the traction control won't allow you to spin the tires when your trying to free yourself.
Trying hard to see this, but still I dont understand. Why would spinning the tires be necessary to rock the car? Would the car (VDC on) not transfer any power to the wheels if it cant get any traction or something, leaving me like a sitting duck in the middle of the snow? If anything, I can see the theory in VDC to be beneficial when trying to do the (if) necessary car rocking.
 

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Turning off VDC/traction control is more beneficial in a non-AWD car. I turn it off all the time in my Accord when trying to get over the high snow bank at the end of the driveway since I have to "push" myself over the high bank.

Most likely with the subie AWD you will not get stuck, but say the snow is deep and you get high-centered on the snow, leaving VDC which includes traction control on will not allow you to rock the car back and forth to break free.

I think you're confusing stability control and traction control. VDC stands for "Vehicle Dynamics Control" which includes stability control + traction control. Stability control will help you keep going on your intended course while the car is in motion. For example when going around an icy curve stability control will help you keep your course while in motion without skidding/sliding. Our B9s also have traction control which applies brakes to the individual wheels when wheel slip occurs. In the same icy curve example traction control will prevent the wheels without traction from slipping if you are still hitting the gas. Traction control is what will not allow you to "rock" the car when stuck b/c it will detect wheel slip and hit the brakes effectively keeping you stuck in place. The reason you have to turn off VDC is that stability and traction control are linked together by the common button.
 

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What I think may also be causing confusion is that a lot of AWD cars/trucks don't actually have stability control nor traction control b/c the AWD system takes care of most problem situations. Our plain jain Legacy SE doesn't have VDC/stability/traction control but obviously does just fine with its basic AWD system. Remember the old Subaru addage, "the AWD shifts power from the wheels that slip to the wheels that grip". VDC just adds some additional electronic trickery to help the AWD system by adding braking to individual wheels and electronic throttle cutoff into the mix.
 

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Great posts, snork. So its not absence/cutting of power to wheels that slip, but actual braking? Informational to say the least.

Thanks a bundle.
 

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i have had the VDC/traction control on and still able to break the back end loose a little around the corners... the little light comes on to say that its working when i do, but it didnt seem to intrusive.

On another note. I had my 97 OB with its winter tires driving around today in 2" of slick snow... no traction control. That thing is just plain fun to drive in the snow. With snow on the ground, there is almost no vehicle that can take it off the line.
 

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njjuliano said:
Great posts, snork. So its not absence/cutting of power to wheels that slip, but actual braking? Informational to say the least.

Thanks a bundle.
Stability and traction control are mostly accomplished by braking, but if you do stay on the gas, they can also cut throttle if it thinks its necessary. But when the throttle is cut it gets cut to all 4 wheels, there's no way to cut power to an individual wheel which is why it uses the brakes.

It should be noted that the throttle cutoff has only been recently added to these systems within the last 5 yrs or so, before that electronic throttle control was pretty rare on cheaper cars (ie: not luxury cars). Older regulars cars have a direct wire linkage from the gas pedal to the throttle body on the engine...thus there would be no way for the computers to cut power. There's still a linkage wire on the pedal, but it's connected to a sensor which in turn the computer uses to drive a servo controller on the throttle body so there's no direct connection between the pedal and the throttle body. The car purists obviously don't like this setup, LOL, but that's what allows for new safety features like VDC.
 

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Thanks for the throttle cut info Snork, I was just about to take ours in for service because I thought it had a problem.
 

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I'm a usual mud driver, with all type of vehicles, including my Tribeca.
When driving slow, if deep mud, you usually need to allow the wheels to spin in order to "dig" and make a "deeper path" where you can find better traction. Imagine you have all 4 wheels without good traction, then the traction control everytime the wheels spin tend to stop them, so you don't go anywhere. If you let the wheels spin manytimes you get that underground traction that let you keep running.
On deep and loose sand I've experienced the traction control intrudes too much and makes you loose inertia, which is very important in this kind of surface. I've tried driving with/without it and got to the conclusion it's better of.

BUT, in any other condition (except deep mud, loose-deep sand), in all kind of SLIPPERY surface the benefits of traction control are huge.
 
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