Last post on May 10, 2010 at 5:35 AM
You are in the Mitsubishi Outlander
What is this discussion about?
Mitsubishi Outlander, Subaru Forester, Car Comparisons, SUV
#4 of 1581 Re: Outlander vs. Forester [chelentano]
Feb 13, 2008 (11:30 am)
That NY Times chart is riddled with errors. Scary that they even published that.
Audi Quattro cannot do a max of 0/100 to 100/0. Audi uses a Torsen limited-slip center differential with a bias ratio of 2 to 1. By design, the limit of that system is 33/67 to 67/33. It's just plain wrong.
Even if the bias ratio was 9 to 1, it would be 10/90 to 90/10. A Torsen is completely incapable of sending 100% to one axle. It's just impossible by design.
Here is a good source from an engineering point of view:
Also, the A3 doesn't use a Torsen at all. It's Golf-based so it uses a Haldex part-time system.
Chrysler Group minivans don't even offer AWD. How old is that chart? Mama-mia.
If it is indeed old enough to include AWD Chrysler vans, then they are also wrong about the Audi TT. Back then the Audi TT actually used VW's system of AWD, since it was a Golf-based system built by Haldex. That defaulted to a 100% FWD split, not 50/50.
Lexus RX300? OK, that gives us an idea about how old the chart is. The RX330 replaced it, and the RX350 has since replaced that model. The last model year for the RX300 was 2003.
Back then, the Audi TT did have a Haldex. So the "Audi all" part is definitely wrong. It's wrong even today - the A3's system is different than the A4's.
The Hyundai Santa Fe's AWD was not full-time back then, either. In fact the traction control only functioned on the front axle, because it was an on-demand part-time system. Don't ask for a source because I didn't seriously shop the Sante Fe at the time.
Volvo uses a Haldex that is not full-time, it also defaults to FWD, like the Audi TT. In fact they use the same supplier. Not surprisingly, Haldex is Swedish. Here's a little write-up about them:
Now, let's specifically look at what they say about Subaru's systems.
First they list the 5 speed manual, call it 50/50 default and 0/100 max. The 50/50 part is actually correct. The 0/100 is not.
Why? Very simple. There is a viscous coupling center differential. It's fluid-filled, and as the two axles move at different speeds, the fluid hardens and locks the two axles together. It's not a thinking system, it is purely mechanical. The 0/100 claim makes it seem rear-biased, but it's not biased at all - it just locks the axles at the same speed. In other words, if it can send 100% to the rear, it can send 100% to the front. The Times should have said 0/100 to 100/0.
Personally, I owned one of those, VC equipped with 5 speed manual, 1998 model. It still uses the same system today. For MY2009, they will add traction and stability control to that model.
How did it work in the snow, out in the real world? Great. Add too much gas in a turn and you could feel the system cycle power fore and aft. If you forced it to oversteer it would send all the power to the front wheels and it would pull me out of the skid. If power were 50/50 I'd be in the weeds because the rear wheels would still be spinning, but that didn't happen. It went to 100/0, i.e. all power to the front wheels, and pulled me safely out of the skid. It was very controllable and a hoot to drive.
Next, the Active AWD system, found on the low-price automatic models. They say 90/10 default (which is correct) up to 50/50 max, which is incorrect. If the front axle was getting 50% of the power or more, the front wheels would have spun like crazy on that ramp. Remember it didn't spin at all. So the front axle was getting 0 power. It should be 100/0 to 0/100.
Third, for the VTD system, 45/55 default is correct (for USA models, some JDM models send 62% to the rear axle by default). 50/50 max is incorrect.
The VW Passat is also wrong, by the way. The latest model uses a Haldex and would not be full-time. The previous model used a Torsen so the limits were 67/33 to 33/67, i.e. same 2 to 1 bias ratio for the Torsen as Audi's.
Any how, for Subaru, they have a bit of an AWD identity crisis, because they are marketing 4 different AWD systems (if you add the STI). They label them all under "Symmetrical AWD", but the truth is each system is different. Effective, but different.
PS I've witnesssed, in person, a Benz 4Matic and a BMW successfully climb those ramps, and also watched a Lexus RX and an Audi A4 (torsen) fail. Yet another error by the Times because they say the Audi can climb one.
#5 of 1581 Re: Outlander vs. Forester [ateixeira]
Feb 13, 2008 (2:17 pm)
As a followup, any of the Subarus with VDC in them, can do 1-wheel powering.
Motorsports and Modifications Host
#6 of 1581 Re: Outlander vs. Forester [ateixeira]
Feb 13, 2008 (4:59 pm)
I think it's an old and outdated report, as 2002 models are referenced.
#7 of 1581 Re: Outlander vs. Forester [ateixeira]
Feb 14, 2008 (3:13 pm)
>> The video in question isn't really a marketing video, it's a dealer training video. It wasn't intended for a general audience, but rather for dealers to learn about Subaru AWD so they can speak intelligently about it to customers.
Yea, right! Bashing other manufacturers for “training” purposes. And then o-o-ps: the “traning” video shows up on youtube and who knows where else? Probably on computers screens of those Subaru sales people so they can show it off to car buyers.
>> I guess I don't see a motive for them to rig the test.
Motive of car marketing: selling more cars. It’s that simple.
>> Plus, how would they even do that? I can see how they could use a FWD CR-V for it to fail, but not how the Forester could succeed by cheating - you clearly see the rollers and wheels moving.
I don’t even want to go there: they’re so many ways to fix the “test”, especially in a movie.
>> That NY Times chart would be nice if it were accurate, but it's riddled with mistakes. Scary that they even published that.
Well, when I see two contradicting opinions: one by the independent New York Times and the other one by biased Subaru enthusiast, which opinion do you think I should trust? The article is one of the best I’ve seen about the AWD systems, the guy definitely knows what he is talking about. In order to dismiss his article, you’d have some credentials. It’s also tough to be wrong for NY Times: they can get sued big Times!
#8 of 1581 Re: Outlander vs. Forester [ateixeira]
Feb 14, 2008 (3:16 pm)
>> Audi Quattro cannot do a max of 0/100 to 100/0. Audi uses a Torsen limited-slip center differential with a bias ratio of 2 to 1. By design, the limit of that system is 33/67 to 67/33. It's just plain wrong. Even if the bias ratio was 9 to 1, it would be 10/90 to 90/10. A Torsen is completely incapable of sending 100% to one axle. It's just impossible by design.
That’s what I am saying, not every person really qualified to dismiss expert opinion. I guess you probably just don’t know the complete picture. Even the http://wikicars.org/en/Quattro says about Quattro: “up to 100% of torque can be transferred to either axle”. It says it there twice. So the guy from NY Times is right.
>> Chrysler Group minivans don't even offer AWD. How old is that chart? Mama-mia.
This 2002 or 2003 article is still newer then that “proof” of yours, which you posted to me in the other thread, which was dated by year 2000 and hosted on some noname site which even could not afford to buy a domain name.
And since we primarily talking about the Subaru, the 2002 Subaru info is almost as good even for the year 2014. According to your own words, Subaru’s AWD system in 1998 was the same, as it’s today. [“I owned VC equipped with 5 speed manual, 1998 model. It still uses the same system today”]
Anyway, Subaru is little slow on new technologies and on innovation. The brand new 2009 Forester uses same-old-same-old 4-speed auto tranny, which means they going to sell that car with dated AWD and dated tranny probably at least through the year 2014! Also Subaru is coming up this year first time ever with its first diesel engine: welcome to 21 century!
>> Now, let's specifically look at what they say about Subaru's systems. First they list the 5 speed manual, call it 50/50 default and 0/100 max. The 50/50 part is actually correct. The 0/100 is not. …Next, the Active AWD system, found on the low-price automatic models. They say 90/10 default (which is correct) up to 50/50 max, which is incorrect. If the front axle was getting 50% of the power or more, the front wheels would have spun like crazy on that ramp. Remember it didn't spin at all. So the front axle was getting 0 power. It should be 100/0 to 0/100.
The NY Times guy is probably right again. In his other article “Introduction to All Wheel Drive systems” he actually calls this auto transmission Subaru’s AWD system “part time”:
“Subaru has for many years been quietly offering radically different AWD systems in the same car, depending on the transmission choice. The manual transmission Legacies and Imprezas use a full time system that is split 50-50 with viscous couplings for limiting slip. In the automatic transmission versions, however, the system is a part time”.
I mean really: 10% of rear axel torque you can barely call full-time. Is it really even 10% or he just rounded the number? I’d call that a fake full-time AWD. Again, there is too much marketing from Subaru, too little technology.
#9 of 1581 Re: Outlander vs. Forester [chelentano]
Feb 14, 2008 (5:04 pm)
No offense but wikki is wrong a lot more than it's right.
Motorsports and Modifications Host
#10 of 1581 Re: Outlander vs. Forester [paisan]
Feb 15, 2008 (7:38 am)
That's good to know, Mike, but I wish you would point this to Ateixeira earlier, when he used a reference to the Wiki site in his last post.
#11 of 1581 Re: Outlander vs. Forester [chelentano]
Feb 15, 2008 (5:08 pm)
Sorry I missed it or I would have. As I said, anytime I've actually check on wikki facts, I realized they are just like anything else on the internet, opinion rather than fact so I dismiss most of what is on there as complete crap cause it has no rep.
Motorsports and Modifications Host
#12 of 1581 Re: Outlander vs. Forester [paisan]
by Stever@Edmunds HOST
Feb 15, 2008 (5:32 pm)
Remember this study in Nature a couple of years back?
That's the granddaddy Wikipedia started by individual volunteer contributors Nature is talking about, not the wikicars thing that was started by Internet Brands to tout their own material.