Hooniverse Asks- What's the Best All-Wheel Drive System?

You ever notice that mountain goats can kick our asses when it comes to traversing near-vertical mountainsides? That’s mostly because millions of years of evolution has proven that those who lack an exceptional sense of balance and dexterity don’t get to reproduce because they’re lying crumpled at the bottom of the canyon. It’s also because the goats have like 4-wheel drive, while we tend to be two-wheel drive and totally lacking in limited slip. Look out below!
Jumping rock to rock along the Rubicon is the milieu of the 4-wheel drive exemplified by the Jeep or Land Rover. But who does that? More realistic and usable in the day-to-day is the All-Wheel Drive made popular by such car companies as Audi and Subaru. While those systems won’t let you rock out with your diff lock out off-road so much, they do allow for 9-10ths on-road heroics when the weather turns to the nasty. It seems like almost every car maker has an AWD option these days, and some are better than others, featuring center diffs with variable torque split and cool-looking badges on the sides.
There’s a couple of different layouts to achieve the goal of having all your tires doing all the work all the time – although the Audi/Subaru model seems to be one of the most straight forward. And actually none of the systems available  have each corner doing 25% of the load. Mostly they bias the power distribution to one end or the other, depending on which one a two-wheel drive edition would favor.
Considering the different takes on AWD layouts – and all the add-on elements that can and are proffered  – what get’s your nomination as the best way to git r done?
Image source: [Paultan.com]

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  1. Syrax Avatar
    Syrax

    qua.ttro.

    1. Battles Avatar
      Battles

      Original small 'q' quattro was decent at the time but they've been playing catchup ever since.
      The current batch of Quattro badged Haldex equipped cars are no better than okay.

  2. Marco Avatar
    Marco

    Subaru symmetrical AWD, it just seems like the most mechanically elegant solution apart from 4 electric motors on each wheel.
    <img src="http://drive2.subaru.com/Win09/_images/chassis.gif&quot; />

    1. Deartháir Avatar
      Deartháir

      Which demonstrates how good their marketing is; Subaru uses a different AWD system for almost every car, so really you'll have to say which Subaru you're referring to. If you're referring to the WRX and STi models, then absolutely. That's a great system, as it's fantastically similar to the original Audi quattro system. Other than that, most Subarus without a manual transmission are basically using a mechanical FWD system with a viscous coupling system that feeds a bit of power to the rear wheels as needed, basically the same as the first generation Lincoln Zephyr/MKZ.

      1. SSurfer321 Avatar
        SSurfer321

        The following question is being posed not trying to be snarky, just more educated.
        Where did you find the information stating that Subaru uses a different AWD system for almost every car? I was under the impression that it is the same basic system under every car, save for the STi.
        I am the owner of a 08 Impreza 2.5i with a manny tranny.

        1. Hoonda Avatar
          Hoonda

          Found this: http://legacygt.com/forums/showthread.php/explana
          Seems to cover most of it.

      2. Peter Tanshanomi Avatar
        Peter Tanshanomi

        When GM rolled out the the Pontiac 6000 STE's sophisticated AWD system, one of the GM engineers famously stated that they'd chosen to develop a "real" planetary center differential, rather than go with the AMC Eagle's "box of Vaseline."
        That's stuck with me, and to this day I can't decide if viscous couplings are elegantly simple or a crude shortcut.

        1. SSurfer321 Avatar
          SSurfer321

          I was once the ashamed proud owner of a Ford Tempo AWD

    2. Deartháir Avatar
      Deartháir

      Dammit, Lucas, put my comment back!

    3. ptschett Avatar
      ptschett

      electric motors on each wheel
      <img src="http://www.jcccw.com/vehicle/more/img/letourneau_lt360.jpg"/&gt;
      R.G.Letourneau (pictured) approves.

  3. jason Avatar
    jason

    Mitsubishi's S-AWC

  4. SSurfer321 Avatar
    SSurfer321

    Currently in production: Subaru
    Potential future applications: In wheel electric motors

    1. dculberson Avatar
      dculberson

      Unsprung weight! Gah! Even with the "low weight" motors that Protean is using, the motors alone are 68 pounds. That's some serious jounce.

      1. Peter Tanshanomi Avatar
        Peter Tanshanomi

        Hydrostatic drive, then?
        <img src="http://www.hydraulicinnovations.com/102.JPG&quot; width="500">

        1. ptschett Avatar
          ptschett

          DO. Want.

    2. Hoonda Avatar
      Hoonda

      Very cool, but the problem with in-wheel electric motors is that you are only getting a maximum of 25% power to each wheel. As soon as a wheel loses traction, there is no torque transferring to other wheels to keep the car moving as it was, just the 25% power loss.
      If you have only one wheel with traction (but it has very good traction), you are trying to accelerate a car with only 25% of its total power. If a car had 200hp worth of electric motors, that would mean you are trying to push it around with only 50hp.
      No thank you.

  5. P161911 Avatar
    P161911

    Does this count as AWD?
    <img src="http://www.cyclesidecar.com/images/content/galleryphotos/full/Unusual/sidecar-willy-300dpi.jpg"width=500&gt;
    The one and only wheel is constantly powered.

    1. Deartháir Avatar
      Deartháir

      I'd say you've answered the question, and the rest of us can go home.

    1. dragon951 Avatar
      dragon951

      I see your ^ and raise you a:
      <img src="http://www.hooptywagon.com/img/cars/porsche/Porsche 959 Dakar 05.jpg" width="500">
      from hooptywagon.com
      Edit: you cheater! that's wider than 500.

  6. fhrblig Avatar
    fhrblig

    I can say it's probably not the AWD in the Suzuki SX4. Don't get me wrong, it works fairly well; the problem is it's pretty laggy. If you are turning a corner and you accelerate, it takes about a second or two to figure out the front wheels are spinning enough to necessitate sending power to the rears. That's with the switch in 'auto' or 'AWD lock', it doesn't seem to make any difference either way. It's still lots of fun in the snow, it'd just be nice for it to be more responsive.

  7. Alff Avatar
    Alff

    Godzilla's Attesa, combining throttle-on oversteer with AWD cornering.
    <img src="http://www.autozine.org/technical_school/traction/tech_pic_traction_skyline.jpg"&gt;

    1. P161911 Avatar
      P161911

      So what are the three little magic boxes that didn't get translated into English?
      Having worked for Japanese companies before, I'm always suspicious.

  8. OA5599 Avatar
    OA5599

    Though I'm partial to Syclones and Typhoons 'cause I've had a couple, I think TV Tommy Ivo got it right.
    <img src="http://www.buicks.net/misc/images/ivo_2a.jpg&quot; width=500>

    1. P161911 Avatar
      P161911

      You hit the NAIL on the HEAD.

    2. dukeisduke Avatar
      dukeisduke

      That picture must be out of "Rod & Custom" magazine. They always had those green-tinted B&W photos. Ah, those were the days. That thing was carried in a way cool trailer, too, with huge floor-to-ceiling windows on the side.

      1. OA5599 Avatar
        OA5599

        <img src="http://www.nhra.com/UserFiles/image/2010/News/July/tv2.jpg&quot; width=500>
        It was hauled on an open trailer. Enclosed trailers came around a little later, and the glass-sided ones later yet.
        There's some good reading here: <a href="http://www.nhra.com/blog/dragster-insider/2010/07/27/tommys-towing-toys/” target=”_blank”>http://www.nhra.com/blog/dragster-insider/2010/07/27/tommys-towing-toys/

        1. dustin_driver Avatar
          dustin_driver

          Hauled on an open trailer by what looks to be a matte gray '60 Caddy. Head. Asplode.

          1. OA5599 Avatar
            OA5599

            This was the tow rig for a state-of-the-early-'60's-art touring machine. Now I often see nicer trailers in the parking lot at my kid's Soap Box Derby races. My own open trailer blows this one away (my cargo is another story, though).

          2. P161911 Avatar
            P161911

            But does your trailer have hub caps and wide whitewalls?

          3. OA5599 Avatar
            OA5599

            It will when I replace the original tires.

          4. ptschett Avatar
            ptschett

            Used to be you could tow things with cars. Now there are places that won't even let you rent their trailer if your "SUV" is the "wrong" make and model.

          5. mdharrell Avatar

            Used to be? You mean I'm doing it wrong now? Why didn't anyone tell me?
            <img src="http://farm2.static.flickr.com/1276/4707393028_2f92e771f5.jpg&quot; width="450">

          6. ptschett Avatar
            ptschett

            Yeah I should have said new cars. Even my old T-bird is rated to take 2000 lbs, but Dodge doesn't recommend towing anything with my manual-transmission Challenger.

          7. OA5599 Avatar
            OA5599

            Tying the issue back to AWD vehicles, the Syclone was rated at zero pounds towing capacity, and externally, it's a truck. The suspension was revised the next year, so the Typhoon was rated to pull a small trailer.

  9. Deartháir Avatar
    Deartháir

    I think the answer has to be Acura's SH-AWD system. It quite literally takes all the best pieces from every other all-wheel-drive system and incorporates them into one. It's the best active torque transferring system I've seen on the market, and really makes almost everyone else look pretty half-assed.
    The problem is that it's hugely complex, and has an appalling number of things that can break, and maintenance costs look like they'll probably be enormous in the long-term. The AWD Prelude, which was something of a precursor to the SH-AWD system, was a monster to maintain, and did require deep pockets. Nevertheless, if you're looking for the best on the market, that's probably it.

    1. skitter Avatar
      skitter

      I have to agree. Audi missed an opportunity with the RS5 torque vectoring rear axle. It uses a planetary on either side of an unnecessary differential, requiring them to keep the center differential as well, nevermind Honda's 2005 system. It's puzzling, though, why they don't also use torque vectoring at the front, where it would have a more pronounced effect. The rear axle winds up fighting the open or limited slip front differential.

    2. Thrashy Avatar

      Seeing as the only AWD car I've ever driven is a borrowed DSM, I don't know if I have room to talk, but I'm inherently suspiscious of a drivetrain that relies on a weird combination of sensor data and hard-coded vehicle modeling and has no mechanical fallback. Not to mention that any weight or complexity savings earned by deleting the center diff is offset by the giant-ass electromagnetic clutches hanging off the rear diff.
      On the other hand, it may be more to do with electronically-controlled diffs taking a hit in the weight formulas of my preferred motorsports. That's scuppered many a hare-bained scheme of mine.

  10. buzzboy7 Avatar
    buzzboy7

    I like the VW syncro system as well as the Subaru Symmetrical system. Both are very similar in mechanical layout except at opposite ends of the vehicle. After working on a latitudinal clutch replacement in a CRV I am very biased against all those turns that power must make. The elegance of the two I mentioned are just perfect. Having the engine-end wheels get power straight out the sides of the transmission like a beetle and the non-engine-end getting power like a standard FR transmission. They are also quite easy to work on.

    1. Deartháir Avatar
      Deartháir

      I hadn't even considered older AWD systems… you're absolutely right. The original Syncro system was actually a damn good system.
      <img src="http://0.tqn.com/d/4wheeldrive/1/0/m/V/1/Dennis_Can_84Bombadier_RR.jpg"&gt;

      1. Kris Avatar
        Kris

        All hail the mighty Iltis!
        I love living in NB. It's like the only province that those things are street legal in. Canadian Forces sold off a bunch (hundreds if not thousands) back in 07 or 08 and they're in the $4K range.

        1. Deartháir Avatar
          Deartháir

          Nope, perfectly legal in Alberta and BC as well. I see them everywhere here in Edmonton, and used to see them all the time in the Kootenays of BC. Still want one quite badly, but they want insane prices for them around here.

        2. BlackIce_GTS Avatar
          BlackIce_GTS

          It is? I've seen one driving around here in BC.

      2. Kris Avatar
        Kris

        Poof?

      3. ptschett Avatar
        ptschett

        That… picture…
        I'll be in my bunk.

        1. Deartháir Avatar
          Deartháir

          Strangely, that was pretty much my reaction to that picture as well…

  11. Feds_II Avatar
    Feds_II

    I'll vote for Jeep's Selec-Trac (which is similar to Mitsu's S-AWC). 2×4 turning the rear wheels when conditions/doughnuts are good, AWD for bad weather on road, 4×4 for light off road, and a low range for when you're really screwed.
    Add a rear LSD and a front air locker and you become unstickable, while still retaining the ability to fix the whole system with a small socket set and a large hammer.

    1. From_a_Buick_6 Avatar
      From_a_Buick_6

      Not having owned an AWD car, I'm a big fan of "full time" 4×4 systems like Selec-Trac. My 4Runner was similar, with a lockable center differential for 4-HI and 4-LO modes, plus 2-HI for dry weather conditions (something lacking from most AWD systems today – they're either part time or something like Jeep's QuadraTrac). Too bad the flakey electronic transfer case and overcompensating traction/stability control made shifting a real pain when I was actually stuck.

  12. tonyola Avatar
    tonyola

    It's got fully active suspension, traction control, anti-lock brakes, collision avoidance, hazard detection, self-repair and diagnostics, and a control system that Mercedes would kill to be able to duplicate. Plus it's eco-friendly, runs on easily-grown biofuels, and is biodegradable.
    <img src="http://upload.wikimedia.org/wikipedia/commons/d/de/Nokota_Horses_cropped.jpg&quot; width=400>

    1. skitter Avatar
      skitter

      Too bad they require a sympathetic driver and have horrible emissions that ruin city streets.

      1. tonyola Avatar
        tonyola

        Climate control is also somewhat lacking despite standard heated seats.

    2. tonyola Avatar
      tonyola

      Now if you want the best traction/weight ratio in your drivetrain, it's hard to beat this. The traction does come at the expense of speed, though.
      <img src="http://upload.wikimedia.org/wikipedia/commons/thumb/6/69/Grapevinesnail_01.jpg/800px-Grapevinesnail_01.jpg&quot; width="400/">

    3. Deartháir Avatar
      Deartháir

      Problem is, there's no way to shut them off. So they keep using fuel, even when they're parked.

      1. tonyola Avatar
        tonyola

        True, but when you put together two properly-equipped units together in the right fashion, you get a brand-new replacement unit that starts off as a subcompact and becomes fullsize with time. Let's see Mercedes, BMW, or Lexus top that!

  13. BЯдΖǐL-ЯЄРΘЯΤЄЯ Avatar
    BЯдΖǐL-ЯЄРΘЯΤЄЯ

    The citroen 2CV Sahara, 2 engines 4WD
    <img src="http://a35.idata.over-blog.com/300×190/3/03/47/69/2cvsaharave6.jpg"&gt;

    1. James Avatar
      James

      What's better than two french two cylinders? Two Northstar V8s.
      <img src="http://27.media.tumblr.com/tumblr_l9hfh0cLgM1qzwba5o1_500.jpg&quot; alt="Mosler Twinstar" />
      Mosler Twinstar.

      1. FuzzyPlushroom Avatar
        FuzzyPlushroom

        If ever a car has needed more rear overhang, this is that car.

    2. Peter Tanshanomi Avatar
      Peter Tanshanomi

      I can haz with V8s?
      <img src="http://www3.telus.net/toronado/UTtwin-engine.jpg&quot; width="500">

    3. tonyola Avatar
      tonyola

      I'd rather have this.
      <img src="http://www.carlustblog.com/images/2008/02/29/cdhondacover_2.jpg&quot; width=300>

    4. Marco Avatar
      Marco

      Another one, the MTM Audi TT Bimoto
      <img src="http://blogs.motortrend.com/files/2007/07/6664220.jpeg&quot; width="500" />

  14. Peter Tanshanomi Avatar
    Peter Tanshanomi

    Can I nominate Honda's Real-Time AWD as the worst?
    <img src="http://hondanews.com/media_storage/JPG/crosstour_powertrain1.jpg"&gt;
    Honda markets it as an ingeniously simple way to implement 4 wheel drive.
    I say it's a hideously complex way to involuntarily drive a FWD drive 99.8% of the time.

    1. Hoonda Avatar
      Hoonda

      The VTM-4 version is a little better since you can lock it out at low speeds (as well as lock the rear diff itself), but the system on the CR-V is pretty weak. Screwing around in the snow, if you stomp the gas there is a discernable moment of the front tires lighting off and understeering like a front wheel drive, then the back tires lighting off and letting you do donuts.
      By comparison, I'm a big fan of the system in my girlfriend's 2003 Highlander. The stability control is a fun killer, but at least the system feels like its throwing power to both axles when you step on it. The traction control basically just uses the ABS to effectively lock the differentials, which makes it do very well off road for what it is.

    2. Hoonda Avatar
      Hoonda

      The VTM-4 version is a little better since you can lock it out at low speeds (as well as lock the rear diff itself), but the system on the CR-V is pretty weak. Screwing around in the snow, if you stomp the gas there is a discernable moment of the front tires lighting off and understeering like a front wheel drive, then the back tires lighting off and letting you do donuts.

    3. Peter Tanshanomi Avatar
      Peter Tanshanomi

      "…a FWD CAR 99.8% of the time."

    4. Thrashy Avatar

      Apparenly, if you let the hydraulics dry out and gum up the viscous clutch thingy ahead of the rear diff, it works pretty much like a regular 4wd system. Not to mention the Wagovan rear diff is suprisingly strong.

  15. dmilligan Avatar
    dmilligan

    Here's my choice in a camper version:
    <img src="http://www.minigrad-models.com/pictures/0/7312/00000014.jpg&quot; width=”600”>

  16. Peter Tanshanomi Avatar
    Peter Tanshanomi

    For the most pure fun, go with this. Just avoid steep descents when traction's poor (like, 3°-plus).
    <img src="http://hooniverse.info/wp-content/uploads/2010/05/huntings_diwheel_lg.jpg&quot; width="500">
    Hey, don't give me that look. All the wheels are driven, no?

    1. mr. mzs zsm msz esq Avatar
      mr. mzs zsm msz esq

      Ha, it reminds me of a Ferris Wheel.

  17. Peter Tanshanomi Avatar
    Peter Tanshanomi

    <object style="height: 390px; width: 640px"><param name="movie" value="http://www.youtube.com/v/csheFaxdSgI?version=3"><param name="allowFullScreen" value="true"><param name="allowScriptAccess" value="always"><embed src="http://www.youtube.com/v/csheFaxdSgI?version=3&quot; type="application/x-shockwave-flash" allowfullscreen="true" allowScriptAccess="always" width="640" height="390"></object>

    1. Peter Tanshanomi Avatar
      Peter Tanshanomi

      Lucas Hoonibbles! You cruel little hamster! Stop playing with that ailing, misshapen little post and give me back my edit and delete buttons, so I can put that poor thing out of it's misery!

  18. Feds_II Avatar
    Feds_II

    how 'bout our 6×6 friend the Pinzgauer? Named for a cow, handles like a beetle.
    <img src="http://imageshack.us/photo/my-images/526/chassis7126x6ds4.jpg&quot; width="500/">
    <img src="http://www.4wdonline.com/Places/Au/Vic/PiCs37/TlngRockyTk.jpg&quot; width="500/">
    Plus, it's run by a ridiculous amount of awesome levers in the cab
    <img src="http://www.4wdonline.com/Steyr/Pinzgauer/PiCs37/6×6.int.jpg&quot; width="500/">

  19. Deartháir Avatar
    Deartháir

    This originally made me go, "WTF is he talking about?" until I went back and looked at my original post. Yeah, I have no clue what I was talking about with the AWD Prelude. Let's just pretend I said what you did about the torque vectoring and leave it at that.
    /need coffee.

  20. Chris Avatar
    Chris

    As far as I know, all Subarus with a stickshift (except the STI) have a 50% torque split front and rear, or each corner receiving 25% of the torque. Very simple and elegant system.
    I can count the number of times I've spun my Impreza's tires on one hand, and I drive it pretty hard.

  21. BGW Avatar
    BGW

    Worst AWD system?
    <img src="http://i.imgur.com/D92wkl.jpg"&gt;
    Hipster on a unicycle.

  22. dragon951 Avatar
    dragon951

    For my serious answer: PTM

  23. facelvega Avatar
    facelvega

    Better for what? Driving at slow speed over rough terrain, or maintaining traction at speed on a road? Totally different problems, and there is no solution that is any good at both.

  24. JayP Avatar
    JayP

    VW and Audi branded it's AWD systems where every AWD Audi as quattro and every AWD VW was 4Motion despite the engine layout and Haldex/Torsen setup.
    I was sad to see the syncro name go away… probably confused the 'mericans.

    1. Deartháir Avatar
      Deartháir

      At least VW made it simpler for a while there. Haldex was 4Motion and Torsen was 4XMotion. Now it's all the same, no matter the AWD system. I miss the Syncro brand as well, there was just something that sounded cool about it.

  25. kvhnik Avatar
    kvhnik

    I've owned a Corolla All-Trac, Subaru Legacy and Audi A6. All seemed to work just fine for a "family truckster". We owned the Corolla for 20 years +1 month and eventually we relegated to rally use and, being so light and with no ABS, could flick with the best of them. The Subaru had a center diff give out which was expensive but otherwise has been noteable by being un-noteable. The Audi I think was the best as far as getting power to the ground but was also the only one with a slushbox…everything happend as smooth as the Queen Mary…and just about as exciting.____The Subaru is still an active member of the fleet and hopefully will be for some time, however the current AWD favorite is a Daihatsu HiJet which has a Hi/Lo range and a locking diff so is a hoot off road. But that is beyond the scope of the question.

  26. dragon951 Avatar
    dragon951

    I like how it points to a 911 C4 as a standard of advancved AWD systems. PTM is not particularly different, just the best tuned, lightest version of the electronic multi-plate center clutch + mechanical diff for the rear axle.
    <img src="http://www.eurocarnews.com/media/pictorials/219/1264-web.jpg&quot; />
    "Chamfered on two levels, these special helical gears can fit the shaft leading to the front axle differential at an angle of 11°, ensuring even more compact dimensions and saving about 6.6 lbs. (3 kg) compared with a conventional power divider."

  27. fede6882 Avatar
    fede6882

    what about the ferrari ff? i kind of like that it has two gearboxs. it sure isn't the most common system, or the cheaper, but a 4wd transaxle in the rear sounds too good to be true.

  28. HRHVelvetJones Avatar
    HRHVelvetJones

    If you just drive your car on paved roads and highways the Acura TL and RL AWD system gets my vote. Giving the power to the outside rear wheel to decrease understeer while cornering. Thats pretty damn good. It's a very good AWD system for snow/ice since it can go from 30%front/70%rear to 70front/30rear% and anywhere in between. http://en.wikipedia.org/wiki/SH-AWD
    If you do a good bit of driving on dirt roads then the Subaru system on the WRX and STI would be the way to go.
    If you do a lot of driving off road then just get a good 4wd truck, suv, or jeep. The Escalade EXT has pretty good AWD. The Ford Explorer with the sport trac is good and the GMC Sierra Denali has AWD also.
    I'm 6'6" so no matter what kind of driving I do it will be in a full size truck or suv. I own a 04 Grand Prix GTP Comp G and after about 30 minutes of driving I cant move after I get out. No room at all. My full size GMC truck I can drive all day since it has plenty of leg and head room. Funny thing the old Honda Civic Del Sol with the seat all the way back I could barely touch the pedals. It was one of the roomiest small cars I have ever been in.
    In the end there is no single best system for everyone. In an engineering point of view my vote goes to the Acura SH-AWD just because of the feature of speeding up the outside rear wheel. A friend owns one and let me drive it and you can just smash the gas in corners and it pushes you around with zero drama. It's just a really fun car. I wish they would build one with room for someone over 6'2" that seems to be the cutoff height for auto designers anymore.

    1. RWB Avatar
      RWB

      6' 5" buddy of mine drives a 2010 Hyundai Accent, says he fits in it better than any large car he's driven; says my Civic is absolutely fine too. In my experience it seems smaller cars are often built to accommodate extreme sizes (height-wise, anyway) pretty easily.

  29. brandon Avatar
    brandon

    Nissan Skyline R32 GTR ATTESA System.
    One reason. It is factory tuned for easily-controlled power-oversteer.
    I am a little surprised this one has not been mentioned yet.

  30. Rust-MyEnemy Avatar

    This thread needs more British.
    <img src="http://www.austinmemories.com/page48/files/page48_10.jpg"&gt;
    Twini Moke.
    I suppose I could've gone all Ferguson on your asses, but prefer the "stick another engine in it" mantra of the Mini.

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