What is VDC?

I want a legacy gt, and looking at 2008 model, it has an option with VDC, what is that, do I need it?

It's Vehicle Dynamics Control. (Stability Control)

You should definitely get it.

do a basic youtube or google search on stability control and you will find a multitude of reasons for it. You can always disable it if you decide to, like if you were to hit the track.

 

On the Legacy GT it is not offered on the manual transmission but standard with the automatic.

It's Vehicle Dynamics Control. (Stability Control)

You should definitely get it.

do a basic youtube or google search on stability control and you will find a multitude of reasons for it. You can always disable it if you decide to, like if you were to hit the track.

 

On the Legacy GT it is not offered on the manual transmission but standard with the automatic.

 

Actually, it's on all models EXCEPT the LGT 5MT.

I wonder why that is? It's offered on the 6MT. I wonder if SOA will discontinue the 5MT for 2009, add VDC to it, or upgrade to a 6MT.

One thing I've noticed with my VDC on (partially in reference to Subie018's comment) is that it helps quite a bit with understeer. Conversely, it does prevent you from going anywhere near as fast in the turns. It's great peace of mind in heavy rain, though.

It's great peace of mind in heavy rain, though.

 

Isn't that what the AWD is for:confused: 75-80MPH in a downpour has never been a problem in any of my Subarus, on real tires;).

 

Seriously though. VDC is a nice feature now that they have it sorted out. The early VDC Outback models didn't work very well.

VDC is stability control. Basically it is always taking your steering angle and comparing against the dynamics of car to make sure you are going in the expected path. If it senses you are skidding/sliding it will do something the very best driver in the world cannot do, brake a single rear wheel to bring your car back to the proper path.

 

A great safety feature.

Isn't that what the AWD is for:confused: 75-80MPH in a downpour has never been a problem in any of my Subarus, on real tires;).

 

Seriously though. VDC is a nice feature now that they have it sorted out. The early VDC Outback models didn't work very well.

 

The car tramlines less and doesn't veer off course while hydroplaning anywhere near as badly. So there I will say I turn it off immediatly whenever I get in the car unless it's sloppy out, though.

Actually, it's on all models EXCEPT the LGT 5MT.

 

Which is basically what I said.

It is not offered on the Legacy 2.5i, and optional on the 2.5i Limited.

Not offered on the LGT 5MT, standard on the LGT 5EAT and Spec.B and 3.0R

 

For '09 it is on all except 2.5GT 5MT.

Isn't that what the AWD is for:confused: 75-80MPH in a downpour has never been a problem in any of my Subarus, on real tires;).

 

Actually no. AWD is not a problem solver for everything, it still has its limitations. You can easily have the rear end step out on a non-VDC equipped Leggy and the AWD will not do much.

I actually e-mailed SOA in 2005 asking why they did not equip the Legacy with VDC. They replied saying that AWD will do anything VDC can do. Hmmm. I wonder why they are taking a pretty big hit and retrofitting it onto the newer models. It's harder to make a system for a car after the car has been designed. Maybe I can email that same rep back.....

 

Anyways, they would have to fit it in by 2010/2011, when it is required by law for all models.

It's Subaru's trademark for stability control. The details vary by model and year.

Which is basically what I said.

It is not offered on the Legacy 2.5i, and optional on the 2.5i Limited.

Not offered on the LGT 5MT, standard on the LGT 5EAT and Spec.B and 3.0R

 

For '09 it is on all except 2.5GT 5MT.

 

I stand corrected.

VDC and viscous couplings dont get along... Inducing brake torque in one wheel would induce a transfer to torque to the other.

 

Thats why its not offered in the 5mt 5 speed.

 

They would have to convert the rear diff into an R180 Torsens or a open diff to use VDC. Torsens can be used because it has an RPM independent bias ratio.

 

Thats the real reason.

I think Subaru had to introduce VDC to continue to receive its outstanding safety ratings here in the USA from the likes of IIHS. I am sure if they didn't have to SOA would never have given it to the rest of the lineup.

I can turn off the VDC in my 07 Spec. B. Is it defeatable in the other models?

I can turn off the VDC in my 07 Spec. B. Is it defeatable in the other models?

 

It is a wonderful feature ... especially up north in the winter.

 

Means winter drifting when turned off.

VDC and viscous couplings dont get along... Inducing brake torque in one wheel would induce a transfer to torque to the other.

 

Thats why its not offered in the 5mt 5 speed.

 

That's true for open diffs as well, though.

 

And, if the stability system is trying to control yaw, then reducing torque on one side and adding torque on the other would be a good thing.