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Hi all: You were all so helpful when I asked a question here regarding buying a used 4.2 rav4. As it turned out, I ended up passing on the deal.

Anyways, I know we all love Toyotas, as do I, but I was wondering if I should widen my SUV search to include other SUV manufacturers. I had never considered a Subaru or Audi but the Subarus are pretty popular here in Colorado so I decided to read up on them a bit. From what I read, I understand that Subaru was a pioneer in the design in AWD and that unlike modern AWD designs that apparently have rear wheel power applied only when slippage is detected, the Subaru (and I think Audi), have constant power applied to both the front and rear wheels at all times. Then, I came across a youtube video which was quite interesting (however it may have been made by Subaru or a Subaru dealer).

In any case, I found the results somewhat disturbing. Only the Subaru was able to successfully climb the ramps and even when other SUV's had slippage of the front tires on the roller, the rear wheels did not seem to "kick in". Do these "on demand" systems really work?? Even so, I can't help but wonder if Subarus (and perhaps Audi's) may have an advantage in this regard. I mean for commuting in snow, wouldn't it be safer if the rear wheels were constantly powered rather than relying for a computer to detect slippage and THEN apply power to the rear wheels?

Thanks for any input.
 

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I never pay much attention to ramp roller tests since they don't involve the car moving. Altho they may perform well in such tests rudimentary AWD systems that apply power to both front and rear differentials full time of necessity require some sort of slippage device commonly called a viscous coupler to allow cornering. Not only is that a wear device but often requires replacing tires only in sets.

Smarter systems such as used on the 4.3 & 4.4 RAV4s apply power to the rear wheels based on the car's accelerometers, in other words the car's movement. If throttle is applied slowly and the car doesn't move there's no reason to spin wheels on rollers uselessly. In that situation on a real hill you'd hit the gas fairly forcefully and during my deep snow tests the wheels spun until after the car stopped moving.

Ice rink tests where the vehicle is allowed to move "naturally" are much more realistic. Under those conditions you'd see both the front and rear 4.3/4.4 wheels spin simultaneously not the rears after the fronts slip.
 

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Thanks all: I read the thread and some hits on the search, but I'm wondering if someone can confirm, in layman's terms, if in fact the Rav4's engages the rear wheels "on demand" as determined when the computer senses front wheel slippage. In other words, do the Rav4's under normal operating conditions apply 100% power to both front wheels and is this true for all generations of Rav4's? If this is true, am I correct that what distinguishes the Subaru and Audi from all the others I have looked at such as the Honda CRV, Lexus RX350 and Kia Sorento is that they always apply power to the rear wheels (I read that is 60/40 front/rear for the Subaru for an AT and 50/50 for the MT).

Also, for the Rav4's, will power shift to the rear wheels only under 25 mph and can you at least "lock" in AWD if you are below 25mph? Again, if someone could please address this in terms of the generations that would be helpful in my used car search.

Finally, may I assume that the board feels Subaru's are a good SUV, particularly for winter driving? I talked with an independent Subaru repair shop and they said one problem is the head gaskets tend to fail at around 100k. The other slight disappointment is that apparently few of the Foresters were made with a V6 (which is what I was hoping to find with the Rav4 after driving both the 4 and 6 cylinder versions).

Thanks again.
 

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I agree with Dr. Dyno about ramp roller tests. About Subarus, they are popular here but we bought a new Forester which was by far the worst vehicle we have ever had. It continually had problems and dealer service departments were incompetent and incompetently run where we were at the time in Southern California.


The Forester has never had a 6 cylinder engine to my knowledge - it has been available as an option in the Outback. And Subaru engines are flat opposed cylinder designs rather than V-cylinder products, at least in the U.S.
 

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When I was buying my RAV4 last year, I looked at the Subaru's (crosstek) only downside I saw was the reliability and price of parts. Ended up with the Toyota, it was cheaper and repairs are expected to be as well.
 

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Thanks all: I read the thread and some hits on the search, but I'm wondering if someone can confirm, in layman's terms, if in fact the Rav4's engages the rear wheels "on demand" as determined when the computer senses front wheel slippage. In other words, do the Rav4's under normal operating conditions apply 100% power to both front wheels and is this true for all generations of Rav4's? If this is true, am I correct that what distinguishes the Subaru and Audi from all the others I have looked at such as the Honda CRV, Lexus RX350 and Kia Sorento is that they always apply power to the rear wheels (I read that is 60/40 front/rear for the Subaru for an AT and 50/50 for the MT).

Also, for the Rav4's, will power shift to the rear wheels only under 25 mph and can you at least "lock" in AWD if you are below 25mph? Again, if someone could please address this in terms of the generations that would be helpful in my used car search.

Finally, may I assume that the board feels Subaru's are a good SUV, particularly for winter driving? I talked with an independent Subaru repair shop and they said one problem is the head gaskets tend to fail at around 100k. The other slight disappointment is that apparently few of the Foresters were made with a V6 (which is what I was hoping to find with the Rav4 after driving both the 4 and 6 cylinder versions).
I can only speak definitely about the 4.3 and 4.4 (except the 4.4 hybrid). (I believe the earlier models are permanent 4WD with a center differential which solves the cornering issue w/o a viscous coupling but with added weight and mechanical loss.)

Starting with the 4.3 the 4WD models operate in front wheel drive until the sensors and 4WD ECU anticipate in advance that rear drive is needed. For instance they always start off in 4WD, releasing the rear drive quite quickly at low speed and throttle. At higher throttle the rear drive stays engaged longer. That's different than reacting to front wheel slippage as confirmed by my full throttle launches on dry, wet and dirt surfaces. If the front wheels are spinning so are the rear. It's easy to test on grass or dirt.
The Lock button will keep 4WD on up to 25 mph whether it's needed or not, but the system anticipates so well most members do not use the Lock.

I'm somewhat familiar with Subarus having owned a Forester, my mom a Legacy and niece an Outback. They all seem to have the head gasket leaks at 100K. My knowledge is that the Forester has a 2.5L flat 4 cylinder engine with a turbo version in the XT models. The Legacy/Outback models also offer a 3.0L flat 6 cylinder. I've heard of people getting rid of them due to terrible fuel mileage.
Winter driving? I once got mom's 2007 Legacy stuck in snow with one front and one back wheel spinning. So much for it's fancy invincible AWD when I had to call for a tow.
 

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Hi all: You were all so helpful when I asked a question here regarding buying a used 4.2 rav4. As it turned out, I ended up passing on the deal.

Anyways, I know we all love Toyotas, as do I, but I was wondering if I should widen my SUV search to include other SUV manufacturers. I had never considered a Subaru or Audi but the Subarus are pretty popular here in Colorado so I decided to read up on them a bit. From what I read, I understand that Subaru was a pioneer in the design in AWD and that unlike modern AWD designs that apparently have rear wheel power applied only when slippage is detected, the Subaru (and I think Audi), have constant power applied to both the front and rear wheels at all times. Then, I came across a youtube video which was quite interesting (however it may have been made by Subaru or a Subaru dealer).
Subaru AWD vs. competitors - YouTube

In any case, I found the results somewhat disturbing. Only the Subaru was able to successfully climb the ramps and even when other SUV's had slippage of the front tires on the roller, the rear wheels did not seem to "kick in". Do these "on demand" systems really work?? Even so, I can't help but wonder if Subarus (and perhaps Audi's) may have an advantage in this regard. I mean for commuting in snow, wouldn't it be safer if the rear wheels were constantly powered rather than relying for a computer to detect slippage and THEN apply power to the rear wheels?

Thanks for any input.

Am i correct in assuming that if they had a 01 rav awd on this ramp it would have " passed " this test?
 
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