Automatic vs. Manual

[Felix]

I have a manual transmission 05 Impreza RS wagon as a commuter car. I'm
reading the literature about the transmissions and it appears as though
the automatic is more advanced in that it can electronically distribute
power to the individual wheels. The manual seems stuck at a 50/50
distribution.
I wanted the manual for vehicle control in snow country, but I'm not
sure that I picked the correct model for my needs. Thoughts?
--Felix

 

[David]

I have a manual transmission 05 Impreza RS wagon as a commuter car. I'm
reading the literature about the transmissions and it appears as though
the automatic is more advanced in that it can electronically distribute
power to the individual wheels.

Hyperbole.

VDC Outbacks may do something similar to that claim. VTC WRXs are fairly sophisticated too.
The Impreza auto does use electronics to control the front/rear torque split (I've read various claims
but it isn't clear to my how much control over that split it really has: can it deliver 90% of the torque
to the rear? I doubt it), but it doesn't actually direct the torque to the slipping wheel. Of the 4 Subaru
AWD systems I'm familiar with the basic auto trans system is the only one with no center differential.
It works well (better than the similar system on a Saturn VUE for example), but it's arguably their
least sophisticated AWD (of course you can argue the other way as well).

 

[ceraboy]

I have a manual transmission 05 Impreza RS wagon as a commuter car.
I'm reading the literature about the transmissions and it appears as
though the automatic is more advanced in that it can electronically
distribute power to the individual wheels. The manual seems stuck at
a 50/50 distribution.
I wanted the manual for vehicle control in snow country, but I'm not
sure that I picked the correct model for my needs. Thoughts?
--Felix

As a general comparison the manual transmission utilizes a viscous
coupled center differntial giving 50/50 power to the front and back
wheels (capable of 80/20 or 20/80 depending on wheel slippage). The
automatic transmission uses a hyrdaulic controlled wet transfer clutch
which supplies 90% power to front wheels and 10% to the back under
normal conditions (this can change from 90/10 or 10/90 given certain
conditions). The automatic transmission determines wheel slippage via
sensors at the four tires. The viscous coupled center differential
functions due to differential heating of a fluid within the
differential to transfer power. While both are capable of transferring
power front and back, the manual transmission should technically have a
bit more lag than the auto. Further, the auto is designed to run
pretty much as a front wheel drive (90% front, 10% back) until wheel
slippage is detected. Frankly I prefer the initial 50/50 split on the
manual which gives me the feeling that I have the power of a 4WD all
the time whereas it seems as if the auto is working against me at times
to keep the car in control. I am sure the newer automatics are getting
better and better, but being an aggresive driver I will take the manual
any day.

 

[BlueSTi]

I have a manual transmission 05 Impreza RS wagon as a commuter car. I'm
reading the literature about the transmissions and it appears as though
the automatic is more advanced in that it can electronically distribute
power to the individual wheels. The manual seems stuck at a 50/50
distribution.
I wanted the manual for vehicle control in snow country, but I'm not
sure that I picked the correct model for my needs. Thoughts?
--Felix

Well, the STi only comes in a manual but I know the AWD system works
great. The DCCD stays in auto mode 99% of the time. I have switched
it to 4 wheel lock when the snow gets really bad. I like having a
manual transmission on really bad weather because it allows me more
control. The opposite side is that with a manual transmission you have
to be a little more judisious about clutch application. It doesn't
take much to get into a 360. BTDT.
All Subaru's are pretty good snow vehicles. Throw on a decent set of
snow tires and you have a snow machine!

BlueSTi
"Scary-Fast"

 

[Edward Hayes]

The default ratio for the 2000 Forester AT is 60/40 according to SOA and
Subaru of Australia. The 90/10 was for the much older models. ed

 

[Bonehenge]

I wanted the manual for vehicle control in snow country, but I'm not
sure that I picked the correct model for my needs. Thoughts?
--Felix

I've had a manual Outback for 4 seasons now. It's simply phenomenal
in the snow, much better than our Jeep Wrangler. You have nothing at
all to worry about.

On a side not, my FIL has an automatic, and the manual version is much
more fun in the rain on twisty roads, as it's AWD is truly engaged all
the time.

Enjoy the car!

Barry

 

[Woody]

I have a manual transmission 05 Impreza RS wagon as a commuter car. I'm
reading the literature about the transmissions and it appears as though
the automatic is more advanced in that it can electronically distribute
power to the individual wheels. The manual seems stuck at a 50/50
distribution.
I wanted the manual for vehicle control in snow country, but I'm not
sure that I picked the correct model for my needs. Thoughts?
--Felix

You made the right choice. We have several years of experience with
two different manual trans Foresters in central NH. They are great in
the snow and have the same 50/50 system that you have.

We have a steep 12% grade 600 feet long gravel driveway that demands
good 4 wheel traction when snow covered. That is most of the winter.

Prior to buying the second Forester, we looked at all of the options
out there, most of which were some form of "on demand" all wheel
drive. I don't want a design that has to wait for the rear wheels to
"slip" prior to transfer of power. Remember high school physics? The
coefficient of static friction is higher than for sliding friction.
Once a wheel slips you have lost some traction. On our steep driveway
once any wheels spin, you have had it.

IMHO the manual trans is: 1. more reliable in itself; 2. gets better
gas mileage; 3. has better acceleration; 4. is more fun to drive; 5.
is less expensive; 6.offers better overall control and 7. is better in
the snow.


Woody; 95FXDS

 

[Bonehenge]

IMHO the manual trans is: 1. more reliable in itself; 2. gets better
gas mileage

I agree with you on everything but the mileage.

Many automatic Subies get equal or better gas mileage than the manual
version. I was very supervised when I learned this. <G>

Barry

 

[Mike G]

Purely a question - has anyone ever stood outside of the car and watched
while someone drops the clutch in the snow hard enough to make the wheels
spin to see if there's any lag between the front and rear?

My cars are a 1991 manual Legacy with 230K and WRX with 30K. I've hung my
head out the door so I could see the rear wheel and hear the front and I
can't notice that there's any lag between when the front and back begin to
spin with either of the cars. I suspect what SOA means by "...3 revolutions
before the viscous coupling fluid heats up enough to lock..." is that it's
3 revolutions of the driveshaft and not the wheels. Frankly, I like having
something that's purely mechanical without the computer getting involved.

Mike

 

[Bonehenge]

I was very supervised when I learned this. <G>

Damn spell check!

I was SUPRISED! <G>

Barry

 

[Woody]

I agree with you on everything but the mileage.

Many automatic Subies get equal or better gas mileage than the manual
version. I was very supervised when I learned this. <G>

Barry

See the Aug 2004 Consumer Reports page 59 where six small cars were
tested: manual vs. automatic for each of the six. For all six
acceleration was better for manual. For five out of six fuel economy
was better for manual. (there was no data on Subaru's)

I assume that the tests were "supervised". <G>


Woody; 95FXDS

 

[Patrick Fisher]

Damn spell check!

I was SUPRISED! <G>

Might as well just quit while you're ahead

 

[Hallraker]

Purely a question - has anyone ever stood outside of the car and watched
while someone drops the clutch in the snow hard enough to make the wheels
spin to see if there's any lag between the front and rear?

My cars are a 1991 manual Legacy with 230K and WRX with 30K. I've hung my
head out the door so I could see the rear wheel and hear the front and I
can't notice that there's any lag between when the front and back begin to
spin with either of the cars. I suspect what SOA means by "...3 revolutions
before the viscous coupling fluid heats up enough to lock..." is that it's
3 revolutions of the driveshaft and not the wheels. Frankly, I like having
something that's purely mechanical without the computer getting involved.

I've got an Auto Subie and I've never seen or noticed any lag. I think the
AWD system on the autos is also tied into the throttle somehow, in that
giving 'er gas will send power to the *rear* first. This is based on
frequent gravel starts, where I'll hear gravel being spit from the rear as I
accelerate to match insane traffic near my home. (My fronts are generally
on pavement during those starts so they don't spin as much, if at all.)

-Matt

 

[Bonehenge]

See the Aug 2004 Consumer Reports page 59 where six small cars were
tested: manual vs. automatic for each of the six. For all six
acceleration was better for manual. For five out of six fuel economy
was better for manual. (there was no data on Subaru's)

We're talking SUBARU AWD cars, not just any cars!

What you say is true for most cars. Subarus use totally different
drivetrains with an automatic than they do with a manual gearbox.

The manual tranny is ALWAYS driving all four wheels. The Automatic
isn't, it's only driving the front wheels on clean, dry pavement.

Barry

 

[Bonehenge]

See the Aug 2004 Consumer Reports page 59 where six small cars were
tested: manual vs. automatic for each of the six. For all six
acceleration was better for manual. For five out of six fuel economy
was better for manual. (there was no data on Subaru's)

Scroll down to mileage:

<http://www.edmunds.com/used/2002/su...?tid=edmunds.u.prices.leftsidenav..6.Subaru*>

Barry

 

[Woody]

Scroll down to mileage:

<http://www.edmunds.com/used/2002/su...?tid=edmunds.u.prices.leftsidenav..6.Subaru*>

Barry

Ok I've been supervised. You are correct about there being a slight
gas mileage advantage for the Subaru autos. First positive fact I ever
heard about an auto transmission. Maybe when I get up into my mid 90's
I'll consider one.

Must be the full time viscous coupling to the rear wheels that creates
some drag on the open road. Not the fact that the tranny is an auto
per se.

Reminds me that I miss the design on my wife's old 88 Loyale GL wagon,
a real 4wd that you engage only when you need it and with low range
available as well. Thankfully they still make real 4wd in full size
trucks but my Dodge Ram 2500 hemi (also a manual) is another story as
far as gas milage is concerned. It probably averages about 14.5 mpg
overall where the auto may average about 14.4 mpg, with a tail wind in
both cases.


Woody; 95FXDS

 

[Yousuf Khan]

I have a manual transmission 05 Impreza RS wagon as a commuter car.
I'm reading the literature about the transmissions and it appears as
though the automatic is more advanced in that it can electronically
distribute power to the individual wheels. The manual seems stuck at
a 50/50 distribution.
I wanted the manual for vehicle control in snow country, but I'm not
sure that I picked the correct model for my needs. Thoughts?
--Felix

This topic gets brought up every couple of months on this newsgroup. Subaru
actually has about three different AWD systems (4 if you count the one in
the STi, but you could argue that it's a variation on the Outback VDC
system).

Three of the four have a central differential to control front/rear torque
split, and one that uses an electronic clutch instead. The one that uses an
electronic clutch alone is the least sophisticated of the automatics. The
least sophisticated of the manuals uses a central diff, with a
hydromechanical slip control, otherwise known as a viscous coupler. The most
sophisticated of the automatics and manuals all have central diffs, with
computer-activated slip control, otherwise known as an electronic clutch. So
in otherwords, all of the most sophisticated AWD systems make use of a
central differential, their only difference is whether there is a
hydromechanical or electronic slip controller. The least sophisticated
system uses an electronic clutch, so that clutch basically performs double
duty as the torque splitter (in lieu of a real differential) and as its own
slip limiter.

So your 5-sp manual has a more sophisticated AWD system than the simplest
automatic system.

Yousuf Khan

 

[Yousuf Khan]

IMHO the manual trans is: 1. more reliable in itself; 2. gets better
gas mileage; 3. has better acceleration; 4. is more fun to drive; 5.
is less expensive; 6.offers better overall control and 7. is better in
the snow.

I doubt that the manual gets better gas mileage than the automatic. First of
all, these days, all automatics have lock-up torque converters, which
effectively eliminates inefficiency of the slippage in the torque converter.
Second, I get the feeling that the manuals are setup more for performance
than fuel efficiency. At 60mph, my 5 speed OBW 2.5L is rotating at around
3000rpm in 5th, when it should be doing 2500rpm or less in most other cars.

Yousuf Khan

 

[uglymoney]

I agree with you on everything but the mileage.

Many automatic Subies get equal or better gas mileage than the manual
version. I was very supervised when I learned this. <G>

Barry

Around town, a well driven manual Subie will kill an auto. On the
highway, you are correct, and it is due to the final drive in fifth
gear being too low.

Manual Subs spin their engines too fast on the highway. Shame they
don't give us an overdrive. I'd like to test drive a new Turbo stick
in the Outback to see if they have improved things.

nate
02 OBW MT5

 

[Bonehenge]

Ok I've been supervised. You are correct about there being a slight
gas mileage advantage for the Subaru autos. First positive fact I ever
heard about an auto transmission. Maybe when I get up into my mid 90's
I'll consider one.

I've never owned an automatic, but facts are facts. Another arena
where the automatics win in Subarus are towing capacity. Many Subarus
are rated for 10-20% higher towing capacity with the automatic tranny.

4wd low? They can keep it on the real trucks. I also have a '99
Wrangler Sport with solid axles and 4wd low. 4wd low is handy on beach
and for pulling my enclosed trailer up a 45 degree incline out of my
back yard. I bought the Outback because I wanted a _car_, for day
to day driving, that would excel in all kinds of weather, seat 4 1/2
people, be easier than an SUV to get my bikes on top, get decent
mileage, insure inexpensively, fit 10' lengths of valuable hardwoods
INSIDE, and still have some overall fun to drive traits. I got all
this for about $22,500, out the door, in December '01.

There are far better offroad vehicles than a Subaru, and making the
Subaru better offroad would eliminate many of the reasons I bought it.
<G>

Barry