"Real Time 4WD" vs. other '08s in class? ...

[PINODY]

For those who have shopped and compared, how does the CR-V "Real Time 4WD" rate to other '08 systems in its class with a 4 cyl.? ... for example: Nissan's "Intuitive AWD?" ... http://www.nissanusa.com/rogue/index.html ... or Acura's "SH-AWD?" ... http://www.acura.com/

[tsmithvt]

Hard to tell. All I'm seeing is the usual Public Relations BS. Maybe some more, in depth information will surface later.:(

[Black Pearl]

I think you are going to have a hard time finding any reliable information on a comparison of the 4WD systems. You will get a lot of opinions but as far as reliable information it may be hard to find. Obviously manufacturers are going to state that their system is best. The problem in my mind is that the cross overs are not considered serious vehicles in the 4WD world and no one pays any attention to them. If I was looking for real 4WD, the CR-V, Rav 4, Rogue, Outback and others would not have been on my list. If you want something that is going to get you through crappy winter weather or do light off roading (more like on roading but crappy roads) they are all more than adequate. Who has the best system? If you find out let us know. My guess is that they all have their strengths and weaknesses and a clear winner may be hard to decide.

[Badgerland]

Also, opinions will vary with owners as does the capability of a certain vehicle with owners. I would bet that someone with vast off-road experience can get a CRV through some things that an inexperienced driver in a serious setup JEEP could easily be stuck in under like circumstances.

[tsmithvt]

It takes a fair amount of digging, but details on how Honda's RT4WD actually works are available. You will NOT find them in popular automotive magazines or in widely circulated Honda publications.

I'm thinking that details about some of the newer cross-over systems might surface with time along with serious, independent testing. Then we can maybe set about answering the OPs question.

[lizzurd]

Here some info on RT4WD compliments of our friends over at the EOC.

http://www.elementownersclub.com/forums/showthread.php?t=32069


Here is a blurb from Honda on SH-AWD

http://www.hondanews.com/categories/764/releases/4244

SUPER HANDLING ALL-WHEEL DRIVE™
The RDX has standard Super Handling All-Wheel Drive™ (SH-AWD™). The RDX system differs mechanically from the RL luxury sedan, but is similar in principle. This all-wheel-drive system progressively distributes the optimum amount of torque not only between the front and rear axles but also between the left and right rear wheels. The result is neutral, accurate steering when cornering under power that front-drive, rear-drive or conventional all-wheel-drive can't equal.
SH-AWD™ counters understeer by rotating the outside rear wheel faster than the speed of the front axle to yaw the vehicle through the turn while cornering. By relieving the front tires of some of the work of turning the vehicle, the system reduces understeer, and handling balance and controllability are improved. In addition, with the cornering load more evenly distributed between the front and rear tires, the total cornering grip is increased. In conventional vehicles, cornering is created almost entirely by the steering angle of the front tires. But in the RDX, additional cornering force is created by the steering angle of front tires combined with the extra drive torque supplied by the outside rear tire.
To deal with high power output, conventional front- or rear-drive systems generally use some type of limited-slip device to maintain traction under power. However, the linking effect of the inside and outside drive wheels in these systems resists turning, or creates understeer. This is a factor that works against the front tires as they attempt to turn the car. Conventional AWD systems have a similar linking effect between the inboard and outboard tires and front and rear axles, causing a similar resistance to turning. By using drive torque to actually help turn the vehicle, the RDX can be more responsive, neutral and predictable, while simultaneously offering all of the usual benefits of all-wheel drive.

[Davecr-v]

I find it is quite good with what most people want 4wd for, basically getting out of plowed in parking spaces and in general getting going. SH AWD is basically a yaw control system similar to what you find on x5's and the EVO's it utilizes steering inputs throttle placment inorder to provide a traction control type 4wd system Nissans is probably very similar. I know the Honda system is a clutch pack coupling system which means in is mechanically controlled and cannot be altered to provide a "4wd lock". I like the fact that I don't have to select 4wd in a sense because it lessens the chance of things going wrong i.e. broken transfer cases and messed up diff's. I like toyota system on the Rav4 which features a 4wd lock which essentially locks in all 4 wheels to be used at low speeds such as getting out of a slippery spot it helps avoid spinning the front tires for no reason.

[sleeksilver]

PINODY, you have some good replys over on hondasuv.com for the exact same question :)

[tsmithvt]

SUPER HANDLING ALL-WHEEL DRIVE™
The RDX has standard Super Handling All-Wheel Drive™ (SH-AWD™). The RDX system differs mechanically from the RL luxury sedan, but is similar in principle. This all-wheel-drive system progressively distributes the optimum amount of torque not only between the front and rear axles but also between the left and right rear wheels. The result is neutral, accurate steering when cornering under power that front-drive, rear-drive or conventional all-wheel-drive can't equal.
SH-AWD™ counters understeer by rotating the outside rear wheel faster than the speed of the front axle to yaw the vehicle through the turn while cornering. By relieving the front tires of some of the work of turning the vehicle, the system reduces understeer, and handling balance and controllability are improved. In addition, with the cornering load more evenly distributed between the front and rear tires, the total cornering grip is increased. In conventional vehicles, cornering is created almost entirely by the steering angle of the front tires. But in the RDX, additional cornering force is created by the steering angle of front tires combined with the extra drive torque supplied by the outside rear tire.
To deal with high power output, conventional front- or rear-drive systems generally use some type of limited-slip device to maintain traction under power. However, the linking effect of the inside and outside drive wheels in these systems resists turning, or creates understeer. This is a factor that works against the front tires as they attempt to turn the car. Conventional AWD systems have a similar linking effect between the inboard and outboard tires and front and rear axles, causing a similar resistance to turning. By using drive torque to actually help turn the vehicle, the RDX can be more responsive, neutral and predictable, while simultaneously offering all of the usual benefits of all-wheel drive.

This is interesting but as usual, they are not telling us how the system actually works. The piece above strongly implies that the brakes are being used to control the torque flow (brake the inside wheel on the rear axle in a turn and you can "push" torque to the outside wheel). This is a passive way of controlling the torque flow and it's cheep if ABS and VSA systems are installed. BUT.. It aint efficient. It's the same as clutch/brake systems used for skid steer. They are not used very much any more because they are not regenerative. They blow torque into heat and that is wasteful and inefficient.

The truth is that you have to be driving pretty much all out for systems like this to make any difference and how many of us do that. This is a very minor improvement over any VSA system which "counters understeer" by applying the brakes on the inside wheels.

The "linking effect" is very minor with an open differential, which is what CR-Vs use. Sometimes (in a heavy pull) that's a disadvantage but in this comparison, "linking effect" is a non issue.

Overall, Honda has done a good job of keeping things simple, light and cost effective. I detect RDX BS.

Thanks lizzurd for the added information. We are trudging towards enlightenment.:)

Ran across some additional information: They use magnetic flux clutches in the rear differential. It's better than using the brakes but still power consumption for very moderate benefit.

[ranken]

For those who have shopped and compared, how does the CR-V "Real Time 4WD" rate to other '08 systems in its class with a 4 cyl.? ... for example: Nissan's "Intuitive AWD?" ... http://www.nissanusa.com/rogue/index.html ... or Acura's "SH-AWD?" ... http://www.acura.com/

I don't know how they compare with the other awd systems, but I own an
f-150 4-wd in addition to my wife's 2006 crv; and while I don't think I would take the crv some of the places I take the truck(couldn't because of the ground clearance) the crv sure does impress me in snow and on ice.

[sleeksilver]

I don't know how they compare with the other awd systems, but I own an
f-150 4-wd in addition to my wife's 2006 crv; and while I don't think I would take the crv some of the places I take the truck(couldn't because of the ground clearance) the crv sure does impress me in snow and on ice.

Your Ford has a true 4WD system complete with a transfer case. The CR-V does not.

They are completely different systems for different purposes.

[Black Pearl]

I don't know how they compare with the other awd systems, but I own an
f-150 4-wd in addition to my wife's 2006 crv; and while I don't think I would take the crv some of the places I take the truck(couldn't because of the ground clearance) the crv sure does impress me in snow and on ice.

I have no experience with 4WD except with rentals, and have very little bad weather driving experience with 4WD. But so far from what I have seen of the CR-V, I am really impressed. Twice my steep driveway has been a sheet of ice and the V went right up it with no indication of trouble. This past Sunday we had a bout of snow showers and heavy wind following rain and freezing rain. We pulled out on a road on top of a hill and the wind was fierce. We were driving along unconcerned, the road didn't look bad at all. First we noticed the other cars tip toeing along in the opposite direction. Then going up a hill two cars in front of us went sideways and started sliding down the hill. We had to come to a dead stop. They finally got going again and we moved along with out any trouble. There were skid marks all over the place and we driving along like it was summer. I wish I could take some credit for skillful driving but so far the V appears to know more about driving in the snow and ice than I do. It has made bad weather a non-issue.

[Hap]

Rankin- totally agree with ya. Have been driving my explorer for many years but this new CR-V is the nuts in the snow and slush!

[Greenzter]

Twice my steep driveway has been a sheet of ice and the V went right up it with no indication of trouble.
Your tires deserve the credit for this. It's all about traction. If your tires are not first rate, and I believe you run new winter tires, 4WD will not help you up a hill on ice. :)

[Black Pearl]

Your tires deserve the credit for this. It's all about traction. If your tires are not first rate, and I believe you run new winter tires, 4WD will not help you up a hill on ice. :)

But I have had new winter tires on previous vehicles with disappointing results. No doubt the tires are a factor, but still I am very impressed with the V's performance.

[Greenzter]

But I have had new winter tires on previous vehicles with disappointing results. No doubt the tires are a factor, but still I am very impressed with the V's performance.
Of course. And so am I.
All I was saying is that tires make all the difference in the world. There are a lot of 2WD vehicles that perform great on slippery surfaces too.
On our V's, if a front wheel looses traction, the rears come in, but what if one of them loses traction as well? On ice? Bound to happen.

Been there, done that. :o