True AWD vs. Traction Control >Subaru and Volvo

Hi,

Went to a Subaru dealer.

They said Subaru uses true AWD - which means it is always on ready to
give power to any wheels.

Volvo is a traction control system - that disengages at 60 km/h.
Volvo uses AWD to prevent from getting stuck and is reactive, whereas
Subaru is preventative.

I am a big Volvo fan, but if Subaru AWD is better, I am interested.

The mechanic used to work for Volvo. He said Subaru and Audi patented
their systems for true AWD.

Has Ford Neutered Volvo AWD?

Any comments about this?

The price difference between a Legacy Wagon and XC70 is HUGE. Double
the price in Canada!! $28000 for a 2007 legacy wagon, $56 000 for a
3.2 litre 2008 XC70

(dealers in the US are not allowed to sell to Canadians -
discrimination anyone?)

Comments?

Tmuld

 

And are you saying the Volvo AWD isn't ready to give power to any
wheels?

Volvo has a traction control system on most if not all cars. It also
offers an AWD system on some cars. Understand that they are different
systems.

OK, Volvo uses AWD to prevent from getting stuck and Subaru uses AWD
as a preventative way to keep from getting stuck. So it would appear
that they both use AWD as a way of preventing a car from getting
stuck. I do not understand your point here at all.

How do you know that one is better than the other. Hopefully you are
not relying on information the adequacy of Volvo AWD from a Subaru
dealer. LOL!!

Good, I'm glad they are patented. I'm sure the Volvo AWD system is
patented too. But what's your point?

Perhaps you can tell us how an asexual mechanical system could
possibly be neutered.

You get what you pay for. If a Subaru is satisfactory to you then
enjoy it. Here in the USA the split between comparably equipped Volvo
AWD and Subaru 6 cylinder Outback wagons isn't anywhere close to 2x.

 

Instead of shooting the messenger (regardless of how biased or
self-serving the message he carries from the competing dealer) can
anyone point to an objective comparison of the two (or three) systems
in question?

Any idea how they are tested or compared?

blurp

 

"blurp" <> skrev i en meddelelse

KLIP

If one really wants an off-roader, then buy a Land Rover or a Toyota
Landcruiser..

Regards
Bjørn J.

 

There has been no shortage of messages on this topic over the past 2
weeks. Most messages claim to prove Subaru has a better AWD system
based on either fuzzy anecdote like his or some hacked home video on
Youtube. I suspect they emanate from the same troll. There is no
professionally done comparison of the AWD systems between those
vehicles that I'm aware of. Absent a good controlled test I think it
is safe to only say performance from the two AWD systems will be
comparable with one performing somewhat better than the other in
certain circumstances. Both have been around for a long time and
there have been no consumer complaints about either system not
providing ample traction when needed.

The real limitation for either vehicle will be ground clearance.
Neither car has an excess of ground clearance and once bottomed out
there is no AWD system that will get the car moving again.

 

Is it true orthodox Jewish people cut a little tip off the exhaust system of
every new car in the family or only the blue ones .

 

Thanks Roadie, an excellent answer! So I suppose then, when comparing
the two vehicles, if one is desperate for quantitative analysis then
one place to look is road clearance. Possibly also wheelbase/turning
circle will affect agility and I suppose curb weight might be a
factor.

Other than that you're left with qualitative analysis re: finish,
extras, ride comfort.

If available, a long-term road test or year-by-year maintenance cost
analysis would also help as would a list of recalls.

blurp.

 

Yup,

I am quite aware a Subaru Dealer might be a bit biased against a
Volvo.

I guess the point is they said their AWD is always on - meaning it
does not rely on slippage of a wheel to trigger activity.
Volvo is a 'part-time on-demand all-wheel-drive'

i.e. in a turn the AWD is still going whereas on the Volvo - that is
not true unless there is slippage. At least that is how it was
explained.

Personally I am Volvo biased as it is a solid performer! I like the
way they look and perform. Just trying to get more info!

I would love to hear from someone who has both vehicles - and if they
notice a difference.

<Rant>

Btw there is a HUGE discrepancy in US prices of cars than in Canada.
They are much cheaper in the US! And our dollar is finally worth more
than the greenback!
Considering the cars are basically the same. Apparently manufacturers
are not 'colluding' to gouge Canadian customers. That is why Canadian
are headed to the US to buy cars.

There is a $10000 CDN saving in buying a Legacy Wagon. Same thing
with base S60.

US retailers are being told NOT to sell to Canadians. Isn't that
discrimination?

</Rant>

Can't we all just get along....

Tmuld.

 

Directing equal power to all wheels all the time would actually seem
to be a very inefficient way to operate an AWD system. Under normal
driving conditions power is not needed at all wheels. It's been a
while, but I believe Subaru uses two kinds of AWD systems. A
rudimentary one like the one you describe for cars with manual
transmissions and a more advenced eletronically proportioned one for
cars with automatic transmissions.

It is my understanding that the Volvo AWD system directs a split
percentage of power to all wheels with the front wheels favored under
normal no slip conditions. Indeed I found an interesting description
on another forum:

"#19, NeoteriX said "...the Haldex system is FWD until the *front*
wheels slip,"

That's a common misconception shared even by some automotive writers.
It's an accurate description of a simple viscous coupling, but not an
electronically controlled AWD system such as Haldex.

Haldex uses parameters such as throttle position, engine speed and
engine torque to distribute torque between the front and rear wheels,
independent of wheel slip. The torque distribution is matched to how
the vehicle is being driven and the driving conditions, whether or not
there is wheel slip.

The Volvo implementation normally directs only 5% torque to the rear
wheels, for example when you're just crusing at a steady speed on dry
pavement. If you then press the throttle hard, Haldex will transfer
more torque to the rear wheels in response to that action. It doesn't
wait until the front wheels slip. Indeed, the purpose of precharging
is to minimize the chance of wheel slip occuring before torque
transfer to the rear wheels.

The above is a description of what Haldex calls normal "torque control
mode". In addition, if wheel spin does occur such as when driving in
snow or other slippery conditions, the Haldex system will act
automatically to eliminate it. This is Haldex's "slip control mode."

 

I owned a Subaru AWD and have owned 2 Volvos with Traction control and
one with AWD.

Subaru AWD is a good system but there are scenarios where it doesn't
work such as when two wheels on one side are on glare ice on an incline.
When Volvo introduced its AWD cars, it took advantage of this bug when
they created a demonstration test to compare various manufacturers.
Since Volvo had AWD and traction control* both, they passed this test.
Since Subarus only came with AWD, they couldn't pass this test.

Subaru responded in 2001 with a Video showing a Volvo struggling to
follow a Subaru up a very muddy hill. What they failed to point out but
you could hear was that with the Subaru they gently applied the throttle
to insure no wheel spin. With the Volvo they gunned the engine to cause
wheel spin to make sure there was no traction.

Volvo S40 AWD, S60 AWD, S80 AWD, V50 AWD, V70 AWD, XC70, and XC90 all
have Haldex AWD and traction control. It is a very advanced system with
an electronic clutch that engages the rear wheels when there is slippage
in the front. It is a very fast system and provides true 4WD when
slippage occurs and 2WD when there is no slippage.

Some Subarus have viscous clutches which is an old technology that can
be unstable when tires do not match. With new tires, it works rather
well. Other Subarus use a planetary clutch in the automatic
transmission. This functions similarly to the Haldex system but is
relatively slow. The Haldex system is faster to react than either of
the Subaru systems, so in that sense, Volvo's Haldex system is more
preventative and the Subaru system is more reactive.

So the mechanics generalizations have no basis in fact. What is the real
difference is that the Volvos have both Haldex AWD and traction control
while Subarus have two different types of AWD and some models come with
traction control while on others it is an option. Traction control is
inheritantly reactive, but most Subarus don't have this system to have
it react.

*AWD cars with traction control not only apply power to all wheels, also
apply braking to any wheel that is spinning at lower speeds. This works
very well on glare ice. On my '95 FWD 850, I was parked on wet glare
ice facing the curb on a street with a pronounced crown. I had to back
up hill to get out. The traction control worked in reverse and got me
out. I was surprised. I thought I would be stuck. So Volvo traction
control even works in reverse.

 

In the strict, dictionary definition of the word, yes. In a practical
(and especially legal) use, no.

It's possible that the automakers are colluding, as you claim, but I
doubt it (nor did you offer any proof of it). There are dozens of
factors. Supply and demand of geographic location for one. Cars are
not all priced the same across the US either, you know. Additional
costs of shipping is also a major consideration (diesel prices,
international law and tax differentiation, etc, etc). And, yes, the
strengthing of the Canadian currency has overweighted the prices of
the cars (by as much as 17%, I've read).

I know of no law that guarantees a non-US citizen the same rights
afforded to US citizens. If an American car dealership refused to sell
a car to an American citizen because of age, sex, religion, yada, yada
then the US courts could become involved. The reciprocal is probably
true in Canada. It may not be fair, but there's no court to hear it.
The US isn't going to extend American rights to a non-citizen and
Canada has no jurisdiction over American businesses.

 

Uhhhhh....simmer down there pardner. I didn't make a statement about
the unfairness of US and Canadian pricing. Someone else did.

 

Uhhhhh...yeah that's why I quoted them and included their name at the
top of my post. It was off-topic, however, and I apologize.

 

Let me preface this by saying that I don't know anything, but in my
opinion if there's any performance difference between the two systems
it will be eclipsed by driver performance, and tire differences.

Me, I have a 92 civic which now sports a limited slip differential,
and I (literally) drive circles around the stuck SUVs in the parking
lot. (Snow tires vs. all weather tires, not my driver performance).

You're absolutely right, the real unbreakable limitation is ground
clearance.

 

I can second that on the tires, in my experience, nothing makes as big a
difference in winter driving as tires. When I put studded tires on my RWD
740 I found I could go just about anywhere. We had a freak snow storm last
year that made a huge mess of things, once the dozens of accidents were
cleared I had no trouble cruising along past the literally hundreds of
abandoned cars. Snow is relatively rare around here so few are prepared and
even fewer know what they're doing.