Subaru AWD

[Dano58]

A thread on an Audi group got me to wondering about the AWD in my
son's '99 Legacy. My Audi A4 quattro system uses a Torsen differential
and has full-time AWD - by that, I mean under normal conditions, all
4 wheels get power, and then it shifts around depending on slippage.
Is this the same for the Subaru AWD in my son's car? Or is it 'part-
time AWD', that is, front-wheel drive until slippage causes power to
also be send to the rear wheels?

Thx,

Dan D
'99 Legacy 30th (son's)
Central NJ USA

 

[Todd H.]

A thread on an Audi group got me to wondering about the AWD in my
son's '99 Legacy. My Audi A4 quattro system uses a Torsen differential
and has full-time AWD - by that, I mean under normal conditions, all
4 wheels get power, and then it shifts around depending on slippage.
Is this the same for the Subaru AWD in my son's car? Or is it 'part-
time AWD', that is, front-wheel drive until slippage causes power to
also be send to the rear wheels?

Nah, the Subie is the good stuff, full time AWD, not part time.

The down side is that it's reflected in your rather lousy fuel
economy.

 

[B A R R Y]

Is this the same for the Subaru AWD in my son's car? Or is it 'part-
time AWD', that is, front-wheel drive until slippage causes power to
also be send to the rear wheels?

Maybe. If it's a stick shift, there's an excellent chace it works like
the Audi system. Automatic transmission? Less of a chance.

Subaru uses 5 AWD systems:

<http://www.subaru.com/allwheeldrive/ver2005/index.jsp>

 

[Dano58]

Maybe. If it's a stick shift, there's an excellent chace it works like
the Audi system. Automatic transmission? Less of a chance.

Subaru uses 5 AWD systems:

<http://www.subaru.com/allwheeldrive/ver2005/index.jsp>

It's an auto. And that site, while interesting, doesn't say WHICH
vehicles and years have which system....

Dan D
'99 Legacy L 30th (son's)
Central NJ USA

 

[Anssi Saari]

Maybe. If it's a stick shift, there's an excellent chace it works
like the Audi system. Automatic transmission? Less of a chance.

Subaru uses 5 AWD systems:

<http://www.subaru.com/allwheeldrive/ver2005/index.jsp>

How do you find out what kind you have? I have an Impreza GT from year
2000, european, stick shift. I'd guess I have the continuous AWD
system, with "Viscous-Coupling Locking Center Differential". I suppose
the other diffs don't have locks, so the car is effectively 2wd on
slippery surfaces?

 

[B A R R Y]

It's an auto. And that site, while interesting, doesn't say WHICH
vehicles and years have which system....

If you don't have the original window sticker, which you probably don't,
check your manual for descriptions, and the presence of an empty "FWD"
fuse location.

 

[Ed]

It's an auto. And that site, while interesting, doesn't say WHICH
vehicles and years have which system....

This is what I hate about the Subaru web site. I have a 99 OBW auto and
a '03 WRX Wgn stick. I still don't know which I have in which car. It
doesn't matter but it would be nice to be able to look it up somewhere.

 

[Carl 1 Lucky Texan]

This is what I hate about the Subaru web site. I have a 99 OBW auto and
a '03 WRX Wgn stick. I still don't know which I have in which car. It
doesn't matter but it would be nice to be able to look it up somewhere.

Your WRX has a viscous locking center diff. It also likely has a limited
slip rear diff.

Your 99 most likely has the 'plain' 4EAT. no VDC, etc.

Carl

 

[Richard]

What does "4EAT" stand for?

Your WRX has a viscous locking center diff. It also likely has a limited
slip rear diff.

Your 99 most likely has the 'plain' 4EAT. no VDC, etc.

Carl

 

[Tcassette]

If it's an automatic, it is full-time AWD. The "normal" power split is 90%
to the front wheels and 10% to the rear wheels, until the front wheels lose
traction. Then, up to 50% goes to the rear wheels.

 

[Carl 1 Lucky Texan]

What does "4EAT" stand for?

four speed, electronic automatic transmission I suppose.
You might dig around at www.cars101.com for more info on
equipment/features of various Soob models.

Carl

 

[John A. Mason]

If it's an automatic, it is full-time AWD. The "normal" power split is
90% to the front wheels and 10% to the rear wheels, until the front wheels
lose traction. Then, up to 50% goes to the rear wheels.
"Dano58" <(e-mail address removed)> wrote in message

This is a broad generalization that is not true for all Subarus. My 02 VDC
automatic does 40/50 normally.
John

 

[Ed]

Your WRX has a viscous locking center diff. It also likely has a limited
slip rear diff.

Your 99 most likely has the 'plain' 4EAT. no VDC, etc.

Again its not important but it just seems strange that the best I can
get is "also likely" and "most likely". Where there that many variations
during model years to further confuse the answer...

 

[Carl 1 Lucky Texan]

Carl 1 Lucky Texan wrote:




Again its not important but it just seems strange that the best I can
get is "also likely" and "most likely". Where there that many variations
during model years to further confuse the answer...

Why do need to know?
I say most likely because, especially with the autotrannies, there are
2-3 variations.
I'm 99% sure your WRX has LSD rear. If you put it on a lift (or raise
just the rear) and spin one side in the rear, look at the other side -
if it rotates the opposite direction + open diff. If it rotates the same
direction = LSD.

Carl

 

[Yousuf Khan]

How do you find out what kind you have? I have an Impreza GT from year
2000, european, stick shift. I'd guess I have the continuous AWD
system, with "Viscous-Coupling Locking Center Differential". I suppose
the other diffs don't have locks, so the car is effectively 2wd on
slippery surfaces?

No, there is also a viscous coupled rear diff on those cars too. So to
summarize, you have the limited slip on the centre diff and the rear
diff, but not on the front diff.

Yousuf Khan

 

[Yousuf Khan]

It's an auto. And that site, while interesting, doesn't say WHICH
vehicles and years have which system....

If you have a /plebian/ model with manual transmission, then you will be
using the system that they call the "Continuous" AWD.

If you have the STi (which only comes with manual trans), then you're
getting the "DCCD" system.

The remaining 3 other systems are for the automatic trannies only.
Low-end 4-cyl models get the low-end "Active" system. High-end 6-cyl
models get the standard "VTD" or optional "VDC" systems. VDC is a slight
upgrade of the VTD, and usually those models will come with a nameplate
that says "VDC" on the outside.

Yousuf Khan

 

[QX]

These may help to tell you exactly what you have:
Googled "Subaru VIN"

http://www.cars101.com/subaru/vin.html
http://en.wikipedia.org/wiki/Subaru_VIN_codes
http://techinfo.subaru.com/html/helpVin.jsp
http://www.answers.com/topic/subaru-vin-codes

 

[Ed]

Why do need to know?
I say most likely because, especially with the autotrannies, there are
2-3 variations.
I'm 99% sure your WRX has LSD rear. If you put it on a lift (or raise
just the rear) and spin one side in the rear, look at the other side -
if it rotates the opposite direction + open diff. If it rotates the same
direction = LSD.

Carl

I don't need to know, I just wanted to know.

I have one other question, does it matter. For instance if I have ABS or
not matters on how I brake. Without I need to pump the pedal instead of
locking up the brake and without I just smash the pedal to the floor
(I'm just generalizing).

So with these different types of LSD or not and locking central diff or
whatever, are there different driving skills needed. In general driving
or only in extreme cases like I have two wheels stuck or one wheel in
the air, etc.

 

[Carl 1 Lucky Texan]

I don't need to know, I just wanted to know.

I have one other question, does it matter. For instance if I have ABS or
not matters on how I brake. Without I need to pump the pedal instead of
locking up the brake and without I just smash the pedal to the floor
(I'm just generalizing).

So with these different types of LSD or not and locking central diff or
whatever, are there different driving skills needed. In general driving
or only in extreme cases like I have two wheels stuck or one wheel in
the air, etc.

Not really. I suppose having open diffs front and back, there are some
rare conditions under which applying a little brake force will actually
be beneficila. I believe another thread here just dealt with that issue.
Its and old trick a lot of off-roaders use I think.
In high performance driving it can alter the drift angle in sharp turns
comapred to other cars I think(less oversteer than RWD, more than FWD).
You might also ask this question in the motorsports forum at
www.nasioc.com or over at www.ultimatesubaru.org .
It IS very important to rotate tires and generally avoid driving on a
donut spare or diferent sized tires. And do not tow with 2 wheels on the
ground - it can destroy the center diff. The manual trannies can, with
some caveats - check you owners guide - be towed with all 4 on the ground.

Carl