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Honda CR-V, Toyota RAV4 or Subaru Forester?

782 messages,  Last post on Feb 25, 2009 at 1:24 PM

You are in the Honda CR-V Forum.

What is this discussion about? Honda CR-V, Toyota RAV4, Subaru Forester, SUV

Messages Page 79 of 79

#773 of 782 Re: [rfrf] by rfrf

Feb 20, 2009 (10:56 am)

Replying to: rfrf (Feb 20, 2009 10:49 am)
I replied:
Sorry for the follow up question, but when in Auto mode and driving at speeds above 25 mph, will the car go into 4WD and transfer power to the rear wheels? I need a little more info on how Auto mode works ar speeds above 25 mph. Thanks.
 
SEE NXT POST
 
T replied:
Conditions of the RAV4 system operation are as follows:
 
Starting from a stop: Drive torque is distributed to the front and rear wheels, with a significant amount going to the rear wheels.
 
Low-speed cornering: Little or no torque is distributed to the rear wheels - this aids in preventing driveline binding during cornering.
 
Straight and steady driving: Little or no torque is applied to the rear wheels to enhance fuel economy
 
Straight-line acceleration: Torque is applied to the rear wheels to enhance traction under acceleration.
 
Additionally, the driver can use a “Lock” button to help the vehicle pull itself out of low traction situations such as sand. Operating the “Lock” switch transmits the maximum amount of drive torque to the rear wheels (approx. 45% of total torque output). From the “Lock”mode, the vehicle will automatically return to “Auto” mode when the vehicle speed exceeds 25 mph, or when the driver deactivates the “Lock” mode by depressing the “Lock” switch.
 
Whenever the brakes are applied in “Auto” or ”Lock” mode, 4WD is interrupted to optimize the benefits of ABS and enhanced VSC.
 
Another feature of the electronic on-demand system is that it can work in conjunction with the VSC system to apply torque to the rear wheels in variable amounts to aid the VSC system in reducing the effects of a vehicle skid condition.
 
I replied:
I thank you very much for the info, but my question is:
When in Auto mode and driving at speeds above 25 mph, will the Elec dem system transmit drive torque to the rear wheels if the system senses slippage or is the auto mode more of a default for when I come back down to speeds below 26 mph? As an example, if I am driving at speeds in the 50s or 60s (like on the highway) andn the front wheels sense slippage, would the Elec on Dem system transmit drive torque to the rear wheels?
 
I got no response. While I may not be the most articulate and nor the most mechanically educated, I have hard earned cash in hand and want to understand how it works before i buy. while i hope that i just did not get a similartly unfamiliar person as a rep to answer my questions, T's response ceratint makes it sound like at speeds above 25 mph, the RAV4 reverts to FWD and that 4WD no longer is avail.

#774 of 782 Re: [rfrf] by blueiedgod

Feb 20, 2009 (10:58 am)

Replying to: rfrf (Feb 20, 2009 10:49 am)
My question to you, whay do you need 4WD at speed?
 
You only need it for added traciton on slippery surfaces when starting from stand still. Once in motion, 4WD is not needed to aid propulsion.
 
In fact, powering rear wheels in turns, or sudden power applied to rear wheels in turns, especially on slippery surfaces will send the vehicle into oversteer. Most people don't know how to react to oversteer, since most cars are dialed in for understeer. Most people slam on the brakes and end up rolling their veihcle over.
 
Are you prepapred to turn the wheel into the steer and continually apply power to come out of oversteer without flipping the vehicle over?

#775 of 782 Re: [blueiedgod] by rfrf

Feb 20, 2009 (11:26 am)

Replying to: blueiedgod (Feb 20, 2009 10:58 am)
You make just the point. Whether the driver feels it is safe or necessary or of benefit to have 4WD engage at speeds above 25 mph, any (potential) driver of the vehicle wd want the info before committing much cash to the purchase of a vehicle that either: a. does or does not have a feature he feels is necessary or b. has or does not have a feature which he feels is unsafe ... which he also wd not be able to disengage.
 
T is a great company and makes great cars ... certyainly among the best ... but T knows whether 4WD engages in Auto mode at speeds above 25 mph or not and T chose to repond (at first, and in the manner they did) and then chose to not respond ... leaving the inquiry open.

#776 of 782 Re: [blueiedgod] by rsholland

Feb 20, 2009 (12:14 pm)

Replying to: blueiedgod (Feb 20, 2009 10:58 am)
Subaru, Audi and others that use full-time AWD would disagree with you on this point. Their position is that AWD can be benefit in terms of performance (accelerating, cornering, etc.), as well as a safety issue under all driving (and all weather) conditions.
 
While it can be argued as to whether AWD aids maximum performance, it certainly makes going "fast" easier and safer. For example I've read several articles in which the writers have said that an AWD Porsche 911 is easier to drive at speed, as compared to the a RWD 911. While the RWD 911 may ultimately be faster, the AWD version is still very fast and is much easier to control at speed.
 
Also take note that some of the world's fastest cars (Porsche 911 Turbo, Nissan GT-R, Bugatti Veyron, etc.) all employ full-time AWD. Now granted, those cars are in a much different league, but the point is the "performance" benefits of full-time AWD do trickle down to more mundane vehicles as well.
 
Bob

#777 of 782 Re: [rfrf] by rfrf

Feb 20, 2009 (1:05 pm)

Replying to: rfrf (Feb 20, 2009 11:26 am)
Just like magic! Since my last post (#775 of 776 Re: [blueiedgod] by rfrf Feb 20, 2009 (10:26 am), I received the following from T:
 
"Yes, at speeds above 25 mph the Electronic on-demand full-time 4WD will transmit drive torque to the real wheel if the system senses slippage to the front wheels."
 
I guess the T rep must have needed some time to check specs ... or someone in T management must be an Edmunds forum reader!

#778 of 782 Re: [rsholland] by rengaw

Feb 20, 2009 (9:57 pm)

Replying to: rsholland (Feb 20, 2009 7:32 am)
Yes, Bob, I didn't explain that correctly. I meant to say that once over 25 mph the system reverted to front wheel drive with the automatic ability bring the rear wheels into play if sensing slipping.

#779 of 782 Re: [rfrf] by ateixeira

Feb 23, 2009 (11:23 am)

Replying to: rfrf (Feb 20, 2009 10:49 am)
Whenever the brakes are applied in “Auto” or ”Lock” mode, 4WD is cancelled to optimize the benefits of ABS and enhanced Vehicle Stability Control (VSC).
 
Sounds very part-time-ish to me.
 
Just like Hyundai.

#780 of 782 Re: [rsholland] by blueiedgod

Feb 25, 2009 (10:31 am)

Replying to: rsholland (Feb 20, 2009 12:14 pm)
Also take note that some of the world's fastest cars (Porsche 911 Turbo, Nissan GT-R, Bugatti Veyron, etc.) all employ full-time AWD. Now granted, those cars are in a much different league, but the point is the "performance" benefits of full-time AWD do trickle down to more mundane vehicles as well.
 
Those vehicles are primarily RWD, or the AWD unit favors RWD unless there is complete slippage, even then, I don't think they send more than 50% to the front.
 
Toyota, Audi, Honda, Hyundai.... are primarily FWD vehicles.
 
The addition of power to he front wheels in a RWD vehicle yields advantage, than addition of power to the rear wheels in a FWD vehicle.

#781 of 782 Re: [blueiedgod] by oregonboy

Feb 25, 2009 (11:33 am)

Replying to: blueiedgod (Feb 25, 2009 10:31 am)
The addition of power to he front wheels in a RWD vehicle yields (greater?) advantage, than addition of power to the rear wheels in a FWD vehicle.
 
For every rule there is an exception. May I nominate the WRX STi and/or Mitsubishi Evo?

#782 of 782 Re: [blueiedgod] by rsholland

Feb 25, 2009 (1:24 pm)

Replying to: blueiedgod (Feb 25, 2009 10:31 am)
They're all full-time AWD, with a RWD bias, usually around 30/70 - 40/60, front/rear. That F/R bias may shift, depending on driving conditions.
 
Bob

Messages Page 79 of 79

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