True AWD vs. Traction Control >Subaru and Volvo

Discussion in 'General Motoring' started by Tmuldoon, Oct 23, 2007.

  1. Tmuldoon

    Tmuldoon Guest


    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?)


    Tmuldoon, Oct 23, 2007
  2. Tmuldoon

    Roadie Guest

    And are you saying the Volvo AWD isn't ready to give power to any
    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
    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.
    Roadie, Oct 23, 2007
  3. Tmuldoon

    blurp Guest

    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, Oct 23, 2007
  4. Tmuldoon

    BJ Guest

    "blurp" <> skrev i en meddelelse

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

    Bjørn J.
    BJ, Oct 23, 2007
  5. Tmuldoon

    Roadie Guest

    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.
    Roadie, Oct 24, 2007
  6. 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 .
    John Robertson, Oct 24, 2007
  7. Tmuldoon

    blurp Guest

    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

    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, Oct 24, 2007
  8. Tmuldoon

    Tmuldoon Guest


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

    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

    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.


    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


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

    Tmuldoon, Oct 25, 2007
  9. Tmuldoon

    Roadie Guest

    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."
    Roadie, Oct 25, 2007
  10. Tmuldoon

    hardl;abor Guest

    hardl;abor, Oct 25, 2007
  11. 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.
    Stephen Henning, Oct 25, 2007
  12. Tmuldoon

    kastnna Guest

    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.
    kastnna, Oct 25, 2007
  13. Tmuldoon

    Roadie Guest

    Uhhhhh....simmer down there pardner. I didn't make a statement about
    the unfairness of US and Canadian pricing. Someone else did.
    Roadie, Oct 25, 2007
  14. Tmuldoon

    kastnna Guest

    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.
    kastnna, Oct 26, 2007
  15. Tmuldoon

    z Guest

    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
    z, Oct 30, 2007
  16. Tmuldoon

    James Sweet Guest

    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.
    James Sweet, Oct 31, 2007
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