Topic: LSD or VDC/TCS?

[Trainman]

 

If given a choice, what would be better in off-road low traction situations: limited slip rear diff or Vehicle Dynamics Control system, in conjunction with a Traction Control System?

Specifically the LSD in the second gen Subaru Forester or the VDC/TCS in the third (current) generation?  LSD is not available in the current Forester 

I am doing my research into a Pathfinder replacement and this is one of the questions I am puzzled by.  The Pathy has a rear LSD, although rather weak it does a reasonable job.  I have no experience with VDC/TCS in any situation, let alone gravel/off-road. My only experience was with the Mystique's rather slick (for 1996  ) TCS.

This is obviously not for hard core off-roading, but just driving on active logging roads at any time of the year.  I can count on one hand how many times the Pathy has been in the bush this last year and a half and none of those times needed 4wd, so time for it to go.

Thanks for any insight.

[inco]

Most of us don't get to drive in the conditions you do so it's hard to visualize or expect what would happen.

On pavement it works very well and it was an extra cost option that I had on the Passat and only once did I ever feel it intruding. Most of the time it did it's job and was seemless. That one time was on an icy patch and I lost it. But it worked and kicked back. Scared the crap out of me because I had forgotten what it would/could do.

I think it was well worth the money and in your situation for those logging mudholes, turning it off or having that capability might be important.

[initial_D]

LSD works well when getting the car out of slippery conditions at slower speed, ensuring 'equal power'  output to each wheel. At high speed, they don't function as well as the electronic aids. The wheels might be applying equal power to the ground, but the drivetrain doesn't know if the wheels are spinning faster than the road condition is allowed. A computer can do a better job at that.

At lower speed, when trying to get the out of a jam, the electronic will eliminate excessive spins, effective stopping the car on the spot.

[Trainman]

LSD works well when getting the car out of slippery conditions at slower speed, ensuring 'equal power'  output to each wheel. At high speed, they don't function as well as the electronic aids. The wheels might be applying equal power to the ground, but the drivetrain doesn't know if the wheels are spinning faster than the road condition is allowed. A computer can do a better job at that.

At lower speed, when trying to get the out of a jam, the electronic will eliminate excessive spins, effective stopping the car on the spot.

Nice thing about the Forester's VDC/TCS is that it can be turned off with a switch on the dash.  But then at low speeds you are left with only traction at one wheel at each end under slippery conditions.

High speed I am not worried about, I would let the renowned Subaru AWD take care of me   

[articsteve]

Electronic TC systems that attempt to replace mechanical LSD ..... BLOW.   However, in the grand scheme of things they are better than no LSD.

[Sir Osis of Liver]

I'll let you know this winter. The main reason for getting the Touring package, was the LSD for me and heated seats for Mrs_T.

[Trainman]

I'll let you know this winter. The main reason for getting the Touring package, was the LSD for me and heated seats for Mrs_T.

The 2009 has LSD in the Touring version?  That would be the one for me then   

However, the Subaru website does not show any LSD for the 2009, only "Differential (rear): Standard open type" across all 4 trim levels (from the specs section of the Subaru Canada web site).

[Sir Osis of Liver]

Nope, I guess not. They may have dropped it for 2009. It is included in the 2008 Touring package on the Outback with manual transmission (I should have added that part, sorry).

[ktm525]

I'll let you know this winter. The main reason for getting the Touring package, was the LSD for me and heated seats for Mrs_T.

The 2009 has LSD in the Touring version?  That would be the one for me then   

However, the Subaru website does not show any LSD for the 2009, only "Differential (rear): Standard open type" across all 4 trim levels (from the specs section of the Subaru Canada web site).

Aftermarket air locker?

[Trainman]

Nope, I guess not. They may have dropped it for 2009. It is included in the 2008 Touring package on the Outback with manual transmission (I should have added that part, sorry).

Me bad, should have looked at what you drive first   

[gotak]

If you are going off road you should be looking for locking diffs.

Many LSDs actually require loading on both wheels to work properly. So in really low traction conditions they don't always work that great.

[dorin]

LSD > VDS/TCS

[mp3butt]

Subaru has made LSD available to Outback for a long time. I believe LSD has been a staple for the current generation. The only outback without LSD is the 2.5i basic. My My07 touring with slushbox has LSD.