4WD and AWD systems explained

kdshapiro

I bet you have great fishing stories to share.

Actually, in my younger days I was an avid fisher youth. So, yeah, I do.

paisan

Can the Outlander "lock" mode be used on dry pavement? If it truely locks in the diffys then it should not be used on dry pavement. Similar to the lock mode on the STi which cannot be used on dry pavement. If it can be used on dry pavement, then it MUST vary the power or the center diffy/clutchpack would burn up in turns.

-mike

chelentano

Nice try taking phrase "up to" that literally and that smile is appropriate here. However, while Mitsubishi provides a variety of numbers for both cruising and extreme conditions, Subaru does not provide any numbers since 2005. Subaru does provide numbers for the 5-speed manual cars, but why it is such a big secret for 4-speed auto Subaru?

paisan

My guess is that it has to do with legal issues. If they say it will do range XYZ, under certain conditions, and you take it out and it never gets to XYZ for any one of a number of reasons, then you'll start sueing them, when in reality it's a variable system and as such VARIES the power as needed.

Bottom line, there is no official documentation, there probably won't be any, and at this point we are beating a dead horse by continueing to ask questions that there are no "official" answers for.

-mike

chelentano

Well, they do offer numbers for 5-manual and 5-auto cars. I guess numbers are just little too low to qualify for a full time AWD. I agree though that legal is probably is one of the reasons.

chelentano

Yea, great story, you are quite a hero racing that lady in a lousy Outlander. Subaru rules!

kdshapiro

The Outlander isn't even offer a full time AWD. You have to flip a switch. I don't want to control the drive train, except to maybe lock center diff for off-roading.

Even if the Forester XT AWD is as low tech as you describe:

1. it's faster than the Outlander,
2. more stable and balanced due to Symmetrical Full Time AWD
3. more fuel efficient
4. behaves like an advanced AWD system

While there are certainly compelling reasons one could find for buying the Outlander over the Forester XT, the Forester makes no pretenses. It does what it does very well, is reliable and and IIHS top pick. Mitsubishi may have put an OK AWD in the Outlander, but like Subaru it's very difficult to tell from the marketing literature. Except we have Mike who has knowledge about the workings of Subaru AWD to give us the real scoop. For all I know the Outlander can equal every AWD challenge one could throw at the Forester. Or not.

This has become how many angels can fit on the head of a pin. I honestly don't care if the Outlander has a "better" AWD. All I know when I stomp on the gas in my XT, I leave most cars in the dust, sun, rain, snow.

kdshapiro

Yea, great story, you are quite a hero racing that lady in a lousy Outlander

Actually she started it, by crowding me on an entrance ramp when I entered the highway. But thanks for the props just the same.

chelentano

i don't think it truly locks in the diff

shazdug

I have had an auto gearbox from a 1999 J Cherokee fitted to my 1995 j Cherokee but the gears change quickly between 1 and 4. It drives ok when used as a manual.
any idea's

dodo2

While the 4WD Lock can be used at any time and any speed and it does not disengage automatically at high speeds, Mitsu recommends to only use it in certain situations - deep snow, gravel roads, to get out of mud or sand and for increase straight-line acceleration (disclaimer- these are my words, but its specified in the Owner's Manual).
I think it's pretty clear that it doesn't "Lock" anything, but sends more power to the rear, all the time (50% more for up to 60% versus up to 40% in Auto mode), while still being fully automated. However, I wouldn't be surprised that this mode has other specific tweaks, but this is just a guess.

There are some interesting videos from Mitsubishi that explain how the system works, but they are in Japanese. I'll look for the links anyway as the images are pretty self-descriptive.

kdshapiro

Having a recommendation for use in snow or gravel probably means increased wear if left in that setting. Kind off an odd recommendation for a full-time AWD system.

dodo2

I said DEEP snow, like in very-low traction situation or if you get stuck. It's more power on demand and probably a more aggressive distribution. Not necessary under normal driving conditions. 4WD Auto is just for that purpose.

kdshapiro

I said DEEP snow

The ground clearance of the Outlander is 8.5 inches, the XT is 8.9 inches. Theoretically the XT can handle deeper snow, which is why I commented on the AWD lock mode.

Even though the ground clearance of the XT is higher, it has a lower center of gravity due to the horizontal engine and symmetrical F/T AWD.

So while the Outlander may have the theoretical advantage in offroad conditions due to the lock mode, the XT has better ground clearance.

ateixeira

Thanks for all the theory and the Mitsubishi press information, guys, but let's look at the bottom line.

How does the Outlander perform off road?

Car & Driver gave it a score of 4 out of 10. Ouch.

Even worse, they said that was because it "felt fragile".

MAN! I can't think of an insult worse than that. Fragile? Despite all this lock business and their Dakar history? That's embarassing.

Quick, change the subject! The V6 is smooth!

And to the person belittling the Tucson, the Kia actually scored higher in off road performance. So did Jeep, Hyundai, Ford, Saturn, Suzuki, Nissan, Honda, and Toyota.

Humuliating for a company also known for WRC success.

Then again, Kia sure has improved a lot lately!

If you want to buy a crossover for a teenage child, and really do not want them to go off road, then I recommend the Outlander.

http://www.caranddriver.com/reviews/comparison_test/crossovers_and_suvs/mud_pupp- - - ies_comparison_test

Cue the "oh they are biased" whining....

paisan

Yoou guys are way way too theoretical. Personally I go for real world experience. I've driven trails in AWD mode in my trooper that Jeep guys got stuck on with solid axles and rear lockers. In the case of the outlander v. forester in snow, 2 things will have more effect on them than any other items.

Tires- If you have a more aggressive tire, it will get you out of snow better, period

Driver Ability- If you know how to drive in snow and offroad conditions you will be able to either not get stuck or get unstuck easier.

I lied, there is a 3rd factor.

Overal ground clearance- I am not talking about 1 single area, if the vehicle gets high centered on snow, ice or mud, you can have the best tires best awd best ability and you won't get unstuck.

So I suggest that everyne who is on here argueing theoreticals and paper stats get out there and actualy drive these vehicles and see which is best for YOU and YOUR conditions.

-mike

dodo2

Your new assertion is a whole different discussion.

I never said the Outlander is better than the Forester. I was just challenging your unsubstantiated claims.

Even though the ground clearance of the XT is higher, it has a lower center of gravity due to the horizontal engine and symmetrical F/T AWD.

This is yet another statement I'm pretty sure you cannot prove. Do you know how high the center of the gravity of any of the cars is? If not, how can you say one is lower or better then the other? Let me guess: your belief. BTW: Mitsu claims that the Outlander's aluminum roof lowers the center of gravity. What’s your spin on that?

Now let me make your day. Run to the nearest newsstand and buy the June Motor Trend. They have a comparison for the compact SUVs. The 2009 Forester won. The Outlander wasn’t included for some reasons. I’m glad the Forester won. I’m sick and tired to see the RAV4 or the CRV winning all the time by default, just because they are made by Honda and Toyota and they should be the best. Out of all vehicles tested, I too think the Forester is the best (although it’s the slowest 0-60 mph which is no surprise).

stever

Hey Shazdug, try asking in the Jeep Cherokee discussion.

The other folks in here are on a mission at the moment. :shades:

kdshapiro

Personally I go for real world experience

Real world experience, any car can make it through virtually anything, at least in the Northeast. I drove a RWD cars with all-seasons for a few winters. While some snow storms it was worse than other, I never got stuck.

The reason I mention it, driving the Forester is like driving on rails on the snow. Didn't hobble along, not afraid to press gas.

But you are correct in a sense. Unless you subject these drivetrains to a torture test, they all look like they would perform virtually identically in real world conditions and all willl probably get through all but worst of blizzards.

paisan

The reason I mention it, driving the Forester is like driving on rails on the snow. Didn't hobble along, not afraid to press gas.

Snow tires on my LGT and I'm gone, when I drive to work in the snow on the NJTP I'm usually doing 70mph which is 10 less than my usual. Problem is once traffic buids everyone does 40 and you almost get hit from idiot drivers so even with good awd you are at risk.

-mike

kdshapiro

This is yet another statement I'm pretty sure you cannot prove

I don't have to. Look at the engine mass in both cars. See which engine sits higher.

Now let me make your day. Run to the nearest newsstand and buy the June Motor Trend.

I'll take your word for it.

I’m sick and tired to see the RAV4 or the CRV winning

While people will cross-shop all of these vehicles, one can come up with their own benchmarks and weights. "Theoretically " If one weighted different categories of items in a comparo and the weight for a good AWD drivetrain was more more than the weight of other items, RAV4 and CRV would sink to the bottom, because they have half baked FWD bias on-demand AWD systems, but they drive decently enough.

The Outlander is certainly a competitive vehicle, but when we get into the nuts and bolts sometimes one looses site of the forest from the trees.

dodo2

Mike, you are spot on again. I don't give a damn about the "paper" comparisons nor the car magazines comparisons, as they are very weak in the way they perform what they call “testing” and how they assess and rank the vehicles.

The only thing I would consider as a valid indication of one vehicle’s or another superiority would be to see them in action, consistently performing better in the same conditions, equally and properly equipped (e.g. tires) and driven by skilled, independent drivers. The rest is worthless waist of time.

dodo2

I don't have to. Look at the engine mass in both cars. See which engine sits higher.

Sure you don't have to, but this makes it just cheap talk.

kdshapiro

Sure you don't have to, but this makes it just cheap talk.

I can't prove a Porsche 911 has a lower center of gravity than the Forester either. But I will bet you any amount of money, it does.

The Outlander is taller, it's engine is taller, and it is not centered horizontally around the drivetrain. Yeah, I feel confident the Forester has a lower center of gravity.

dodo2

I can't prove a Porsche 911 has a lower center of gravity than the Forester either. But I will bet you any amount of money, it does.

You picked a very good example to make your point. :confuse:

The Outlander is taller, it's engine is taller, and it is not centered horizontally around the drivetrain.

Did you actually check the numbers to say the Outlander is taller? I'm asking as I didn't check myself, but my visual impression is that the Forester is a tad taller.

psychogun

No offense, that comparo was a joke. Not only for the reason that a CUV doesn't really belong off-road, but for the testing procedure used (they managed to get the Jeep Liberty stuck, pathetic).

Objective? Not on your life.

They lack what apparently every auto rag lacks today. Specific and defined metrics for each test point that are consistently applied and measured against a defined benchmark (not to mention duplicable). It's known as the scientific method.

C/D makes stuff up as they go. The "fragile" comment is a great example of this. What does it mean? How is it measured? What is the automotive benchmark or definition for a fragile feeling vehicle?

As mentioned before. Drive these CUV's, not because of what some magazine says, but because we are lucky enough to have all of this choice. That said, I personally would be most interested in the Forester and the Outlander.

kdshapiro

Did you actually check the numbers to say the Outlander is taller? I'm asking as I didn't check myself, but my visual impression is that the Forester is a tad taller.

This morning I parked next to an Outlander. The roof was higher, but I didn't take out my tape measure.

kdshapiro

C/D makes stuff up as they go. The "fragile" comment is a great example of this. What does it mean? How is it measured? What is the automotive benchmark or definition for a fragile feeling vehicle?

Saying a vehicle is fragile is like saying a particular food dish tastes great. Each auto is more than the sum of their numbers and there is an objective as well as subjective part. And, what you consider a deal breaker to me could be a deal maker.

What tastes good to me may be vile to you. The mags will be slammed any way they write a review.

comem47

I can't prove a Porsche 911 has a lower center of gravity than the Forester either. But I will bet you any amount of money, it does.

Mitsubishi seems proud of the fact they lightened the roof by 11 lbs using aluminum (implying the center of gravity is measurably lower) While I like the handling of my Outlander, I'm not sure how much 11 lbs actually lowers the center of gravity as to be significant. I do know it feels much better than the Durango I had (not to mention the better MPGs

dodo2

I checked the numbers and the Outlander is indeed slightly taller (less than an inch difference).

ateixeira

The whole point is for them to cut through all the PR spin from the manufacturer and give us their opinion on how the vehicles perform on the road (and off).

We can't just take the manufacturer's word for it. I'm sure Yugo corp. said their cars were great.

C&D measured ground clearance, angles of approach, departure (which they complained about), and breakover, things like that. So they do also include objective info along with their subjective evaluations.

I'd love to get these two (actually, all compact crossovers) on one of those ramps that simulate driving on ice, but that's not as easy as it sounds. I've challenged other Outlander owners to get out to a 4x4 meet, locally, and try it out.

Videos that show a Tribeca and a Legacy climbing up such a ramp with only a single wheel with traction prove the effectiveness of its AWD. Sure, a Subaru dealer put it together, but it was a dealer that put that Outlander video showing the snow boarder being towed, also.

The 2008 Forester video only showed it climbing with one axle having traction, so it did not test the side-to-side torque transfer. The 2009 model adds traction control, so it's time for a re-test.

So its AWD works front-to-rear, but I want to know if the traction control system can transfer power side-to-side on one of those ramps, like the Tribeca and Legacy managed.

Nothing Subaru says can prove that. Car mags often just quote from the press materials the PR folks from Subaru give them.

I want to see a 2009 Forester on one of those ramps.

I'd like to see competitors try the same thing. Toss all the theories out the window, and then put up or shut up.

I've personally witnessed both Audis and Volvos fail that test.

psychogun

Don't get me wrong, I don't really care for the manufacturer PR spin either.

The problem is, is that the auto rags have become part of the PR spin machine.
That's why I maintain that there is no more independent or objective testing present in the automotive press (including Consumer Reports).
Not to mention that marketing companies like JD Power, Auto Pacific, etc. just aggravate the situation.

I wholeheartedly agree with you about getting owners together and repeating the ramp test. It could be a beautiful fact-finding experiment (plus it would stick it to the PR machine and the auto rags). :P
Though I would shy away from calling it a challenge. In my humble opinion, that would make it sound like a competition. That would only bring egos into play and go downhill from there.
If I lived in your neck of the woods and owned one of the vehicles in question, I would definitely attend. I own a Civic and an Odyssey (soon to be traded in) BTW...

kurtamaxxxguy

Agreed on the Ramp test redo. Would also tell us how long it takes the '09 Forester to brake spinning wheels (some of the Subaru test track videos suggest this can take a few seconds or so).

kdshapiro

Would also tell us how long it takes the '09 Forester to brake spinning wheels (some of the Subaru test track videos suggest this can take a few seconds or so).

Just as a side note, years ago there were threads on the Jeep boards where it was suggested that until the diffs warm up the vicious fluid inside it will take seconds to transfer power. I wonder if that is the case here. Once the fluids warmed up, transfer was fairly quick.

With the vehicle stability controls doing the braking, they should be able to detect wheel spin and apply brakes similiar to the time it takes ABS to kick in. But this is more conjecture until this is seen in a real situation.

chelentano

>> Videos that show a Tribeca and a Legacy climbing up such a ramp with only a single wheel with traction prove the effectiveness of its AWD. Sure, a Subaru dealer put it together, but it was a dealer that put that Outlander video showing the snow boarder being towed, also.

You keep talking about that marketing video made by Subaru. Forester AWD appear to be good there, and other cars do not perform well there. The result is too black-and-white to be true: not convincing.

So if you like videos, let's take a look at some, and these videos were not made by Subaru:

Forester got stuck in snow:
http://www.youtube.com/watch?v=ahOofosxeP4&feature=related

Forester got stuck in snow again:
http://www.youtube.com/watch?v=oJ2Ed-0uu5M&feature=related

Forester could not climb hill, until it got off the wet trail:
http://www.youtube.com/watch?v=-tMgWtlxeb8&NR=1

Forester got stuck in mud once again: call tow truck!:
http://www.youtube.com/watch?v=uxciE14BrGg
.

…And these videos were not made by Mitsubishi:

Outlander cruising effortlessly through a heavy snow:
http://www.youtube.com/watch?v=k3arUMr2PsI

Climbing uphill in snow? No problem:
http://www.youtube.com/watch?v=7RUrT_0tvn8&feature=related

Outlander going through the tough mud. Effortless:
http://www.youtube.com/watch?v=W0kdzSklDWE&feature=related

kdshapiro

Since the footage was from a previous generation Subaru, without any knowledge of underlying ice, tire conditions and exact AWD drivetrain configuration, I offer this from MT: check out the quote.

http://www.motortrend.com/roadtests/suv/163_0306_crossover_wagons_comparison/car- - go_space_conclusion.html

Neither of these hearty wagons had much problem negotiating the snow-covered trails close to the chalets, with AWD clawing them up hills and into small valleys. On packed powder, they were about equal, but, in the soft stuff, the Mitsubishi spun its tires, while the Forester kept plowing along.

It's likely the Outlander would have been in the same predicament as the older generation Forester, if it were in the same place at the same time. Even then the consensus was the Forester had the better AWD.

comem47

Well think these videos prove the Forrester is not invincible, but that said, no vehicle is. Outlanders/Forresters are hardly serious off-road vehicles. Also, a good driver can make a so-so car look good and vice versa. I'd particularly like to see the tires on these vehicles. If you want to do real good off road (outside of locking diffs and higher ground clearance) you better be prepared to have some aggressive tires that might sing terrible on the highway (I don't care to do that). To be fair to all, you need the same person driving the cars objectively, at the same location with equal tires. I did not buy my Outlander to play with the big boys. Rather, I found it did a good job of towing my loaded snowmobile trailer uphill just fine and does a great job of getting much better year round MPG than both the 4WD Durango and Dakota I previously had in the family fleet. (13-15mpg). (and no, it was no big deal to engage the part time 4WD when needed on them, but don't try to do figure 8's in them on a dry parking lot with the part time 4WD like you can with Forresters and Outlanders full time systems... but they did great with low range lock when needed!!!

chelentano

Ateixeira keeps referring to this Subaru marketing video which promotes supremacy of Forester AWD. That video is also about the previous generation of Subaru, not the current one. That Subaru marketing video also has no information about Forester drivetrain/tire configuration and even about other cars configuration which all took part in that "test".

So the videos I posted indicate that that marketing climbing "test" on ramp is just a show, but on these real life videos Forester is little less then impressive, it constantly in need of tow service. There are probably a dozen or two of Outlander off-road videos on Youtube, and I have not seen any "stuck in mud" situations. That's speaking of videos.

Also there were no known improvements to the AWD system in current 2009 generation to assume that it would perform any better. In fact it appears the new generation of Forester has its AWD system downgraded: it does not have the Limited Slip Differential - center/rear anymore, and no more torque split specs published.

chelentano

You right, both vehicles don't pretend to be a serious off-road performers. Still these evidently armature videos show that the Outlander is very capable. Cruising at night through that field of one foot snow, or through that russian mud in the other video: I'd say it's quite spectacular performance for CUV. Don't forget, that this Outlander was selected as support vehicle for Dakar Rally with very minimal modifications, so they probably aware that it could get through the desert.

psychogun

Over the past 2 or so pages this thread has really strayed.
Instead of 4WD & AWD systems explained, this has turned into a juvenile "mine is better than yours" cat fight.
I was under the impression that this was supposed to be informative and helpful, not for bashing, making unsubstantiated claims, or posting misinformation.
Am I alone here?
Hosts?

tidester

I'm not sure how much 11 lbs actually lowers the center of gravity ...

It's easy enough to estimate. Just divide the 11 pounds by the weight of the vehicle and multiply by the height of the roof above the center of gravity. Roughly speaking, it would be 36" × 11/4500 or about 0.088 inches.

Also, comparing the center of gravity of two different vehicles is not particularly illuminating. Stability considerations depend on center of gravity AND wheel base.

tidester, host
SUVs and Smart Shopper

kdshapiro

Ateixeira keeps referring to this Subaru marketing video which promotes supremacy of Forester AWD

But that doesn't mean any vehicle in the world won't get stuck when it gets into conditions over it's head, even with a locking center diff and four wheel lockers. I had a snow plow stuck in front of my house in the Blizzard of '96 for two days waiting for front loaders to bail it out.

So the videos I posted indicate that that marketing climbing "test" on ramp is just a show, but on these real life videos Forester is little less then impressive,

That also was an older Forester (non-US spec at that). So what it got stuck. The real question is would the Outlander from the same year get stuck as well. I would bet the farm on it.

In fact it appears the new generation of Forester has its AWD system downgraded: it does not have the Limited Slip Differential - center/rear anymore, and no more torque split specs published.

If the combination hardware and software make the vehicle even more capable than before who cares if there is no LSD? We can certainly discuss this is tests and comparos come out.

In the meantime, notice the MT comments on the Outlander AWD system. In the same conditions the Outlander spins it wheels while the Forester plow ahead. Here is an objective opinion of the two side by side in the same conditions. Not a video in some unknown place taken with an unknown year vehicle with another video in another unknown place taken with another unknown year vehicle.

rsholland

A lot of what I saw here appears to be tire related. We don't know what kind of tires those Foresters had—or more important what condition they were in. They could be original tires, which could be well worn—not a great thing to use in slick muddy conditions.

I've had my Forester in some muddy situations that I was apprehensive about, but it got through just fine. In 12 years of Subaru ownership (2 Outback Sports, 1 Forester, 1 WRX), I've never gotten stuck in the snow.

Bob

rsholland

The front/rear power split on non-VDC/VDT Subaru automatics has been an ongoing debate for years. So I contacted SOA, and posed that question. There were two e-mails between myself and SOA. They are posted below.

Bob

__________________
__________________

There is a debate going on over on Edmunds.com Subaru forums about the default front/rear AWD power split on Subaru automatics (not VDT or VDC). Some say the power split is 90/10, front/rear; while others say it is 80/20, front/rear. Also, can that change to 10/90 (or 20/80) depending on traction conditions?

Could you please clarify this, as Subaru makes no mention of it in any of their marketing brochures.

Thank you.

_______________________________________

Thank you for visiting the Subaru of America Web site and for your message.

The AWD System on our automatic transmission models not equipped with VDC or VTD do not have a default power split. For these vehicles, the power split is always fluctuating due to conditions. This is why we do not list a default setting in any of marketing brochures, Web site, etc.

If you need any future assistance, please let us know.

Sincerely,

xxxxxxxx
Subaru of America, Inc.
Customer/Dealer Services Department

_______________________________________

Thanks xxxxxxxx.

Then the question is: What is maximum percentage of power sent to any given axle? Is there ever a situation in which either the front axle or rear axle never receive any power, such as 0/100 or 100/0?

Thanks again.

_______________________________________

You are welcome. I can answer part of your question; but, not the maximum percentage to any given axle. It will NEVER be 0/100 or 100/0. Each wheel/axle will always have some power. It is never that all power is to either axle. Hope this helps!

Sincerely,

xxxxxxxx
Subaru of America

stever

this thread has really strayed

It was even worse over in the Subaru Forester vs Mitsubishi Outlander discussion. At least now the bashing is focused on traction.

People do get excitable about their cars - keep reminding them that hyperbole and potshots doesn't help their cause.

dcm61

People do get excitable about their cars - keep reminding them that hyperbole and potshots doesn't help their cause.

It's kinda like when people brag about how much snow they got, how many runs that got in, etc.

stever

Hey, I resemble that remark!

I drove my AWD up to the ski hill about 35 times last winter. A few times the AWD came in pretty handy, but FWD and snow tires or studs would have done me fine. I carry chains but I'd rather not use them if at all possible - and most AWD/4WD systems, no matter how they work, will help you avoid that. Assuming you still drive for the conditions.

I see there's yet another place to bog down in the details now:

kurtamaxxxguy, "SubaruAWD_variations_and_comparisons" #1, 16 Apr 2008 1:26 pm

I don't know about the dumb underscores in the discussion title though. :P

dodo2

Finally some credible information. However, this applies to the non-VDC setups which do not include the 2009 Forester. IIRC all 2009 models have VDC (please correct me if I'm wrong).

Is it possible that this changed for the 2009 Forester w/4AT and VDC and the AWD system in this vehicle could send up to 100% of the power to the rear wheels?

The reason I'm asking is that this is what Edmunds.com tell us in their article:
First Drive: 2009 Subaru Forester XT.

Excerpt:

"When the Forester comes with a four-speed automatic transmission, the torque split for the AWD system constantly varies according to acceleration, deceleration and wheel slip, and as much as 100 percent of power can be directed to the wheels with the most grip."

According to this, if the front wheels have no traction and the rear wheels do, up to 100% of the power could be sent to the rear.

Do Edmunds editors know something that we don't know or ..... oh ... well ... once again they post inaccurate information? :confuse:

chelentano

I think you are right: all 2009 Foresters have VDC, so the email does not help much. As for the article it appears to be inconsistent with any other sources.

rsholland

However, this applies to the non-VDC setups which do not include the 2009 Forester.

Good question. I just fired off another e-mail to SOA asking them this. Should hear back on Monday or Tuesday. I will again post the response.

Bob