[Empz]

First snowfall ever with the MO!

Toronto got dumped on the day before ... had about 3 inches of snow or so ... got a chance to 'play' with the MO!

The AWD isn't what I expected ... for one thing ... I'm not a huge fan of the AWD lock only fuctional to about 19 KMH ...

Now what else I find interesting is that my MO fishtails like my Maxima ... I don't even feel the AWD until like 3 seconds after the fishtail (by this time I'm already correcting the steering)

I'm comparing this to my Pathfinder ... with the ATTESA 4WD system ... I find it much better at giving power to the slipping wheels ... I don't even fishtail as much AND its RWD in Automode, the 4WD kicks in much sooner ....

I guess nothing's perfect ... don't get me wrong ... I love my MO ... but I guess it still has it shortcomings ... its almost better than the Pathfinder in everyway .... 'cept for its AWD/4WD!

-E

 

[senza]

Empz - the fishtailing you experience is not caused by the late application of AWD but by the quick application...the spinning of the rear wheel(s) and the resulting loss of traction permits the rear end to fish tail...this is a characteristic of the MO you have to get used to...a FWD based AWD system handles quite differently than a RWD based AWD system...

 

[EasternPA]

Empz, I'm wondering if you're describing the VDC kicking in to get you out of the slide. Once you enter a pretty good slide... and I mean it really has to let go... if you have VDC, you should feel one or more brakes literally apply themselves and you should regain control immediately after that happens.

Now when talking AWD: if I try to take off straight ahead on slick roads, I literally get just a few degrees of tire spin before it is immediately stopped... about 1/4 second.. and feel the punch from the rear coming in with power. Certainly no 3 second delay there.

The 3 second wait in a good slide before recovery sounds more like the way VDC behaves to me, and I've had it save a few slides on greasy wet sharp curves.

 

[NVMYGT]

Empz, I'm wondering if you're describing the VDC kicking in to get you out of the slide. Once you enter a pretty good slide... and I mean it really has to let go... if you have VDC, you should feel one or more brakes literally apply themselves and you should regain control immediately after that happens.

Now when talking AWD: if I try to take off straight ahead on slick roads, I literally get just a few degrees of tire spin before it is immediately stopped... about 1/4 second.. and feel the punch from the rear coming in with power. Certainly no 3 second delay there.

The 3 second wait in a good slide before recovery sounds more like the way VDC behaves to me, and I've had it save a few slides on greasy wet sharp curves.

This is exactly the same reactions that my MO exhibits. I've tried to get the rear end to step out, but as soon as it feels as if it is going to do it the VDC kicks in with disapproving grumbles and I'm off in a straight line again.

 

[mozman]

Would someone just quickly give an overview of how the AWD drive system works on the Mo. Unfortunately, I did not see the details on Nissan's web site. I thought that their is intial power distribution to all 4 wheels (like 75%F/25%R) and then switches to 100%FWD when cruising or giving more power to the rear when condition warrant it.

Other AWD cars in how I believe they operate:
Acura MDX - works 100% FWD from stop and AWD power distribution kicking in when needed.

Infiniti G35 & FX- approx 25%F/75%R split from stop. Switch to 100% RWD when cruising and power distribution when needed.

Do I have all this straight?

 

[elliotgb]

Empz

You may want to read this post that Jaak put together. It's a pretty good overview of Awd/Vdc, etc:

http://www.nissanmurano.org/forums/showthread.php?s=&threadid=1762

 

[EasternPA]

Sounds about right, moz, but I was under the impression that the Murano runs 80/20 F/R by default, until conditions warrant otherwise; never reaching 100% front. I'm willing to be wrong, though.

 

[mozman]

That's great stuff on VDC and other stability control functions, but I didn't see any talk about the AWD.

As for the AWD power distribution numbers, I was just throwing approximations of where i thought it was. I was close.

 

[Tyler_Canada]

The AWD system in the MO is 100% front unless traction is lost.
If you lock the AWD button, the power is 50%/50% until 19mph (30kph).

I can kick the rear out quite a bit on my MO without the VDC coming on. It's only if I slide the front end that the VDC comes on. I like it this way, because I like to kick the rear out (great for parking in tight spots!).

 

[EasternPA]

I like it this way, because I like to kick the rear out (great for parking in tight spots!).

You've been watching too much Ace Ventura!!!

 

[Gonzo]

I wish I did more research.... I had not realized how easy the MO can get stuck even with the AWD. I would have puchsed the FWD drive instead. Oh well live and learn.

Regarding those that asked about the AWD kicking in at 19 MPH... Why???? Remember you really shouldn't need AWD at higher speeds... it doesn't do much for you. At the lower speeds you would need to to help pull yourself through. Don't think that you are invinsable on the highway in any AWD car... (of course VDC helps)

I thinnk that the MO will still kick in AWD at any speed when it senses slip. Someone correct me if I'm wrong?

As I understand it, the MO is 100% FWD until it detects that slip. That is nice since using FWD only helps with the better fuel economy.

 

[silverz50]

The AWD system in the MO is 100% front unless traction is lost.
If you lock the AWD button, the power is 50%/50% until 19mph (30kph).

I can kick the rear out quite a bit on my MO without the VDC coming on. It's only if I slide the front end that the VDC comes on. I like it this way, because I like to kick the rear out (great for parking in tight spots!).

So if you put it in lock and go over 19 mph, it will bounce right back to FWD?

 

[NVMYGT]

Gonzo,
From what I remember in reading this thread and Nissan's website, the AWD in the MO is 100% front until it detects a necessity for power transfer or if you have the AWD lock engaged. With this said, I believe that even if you have AWD lock engaged the MO will still respond to the need for AWD over 19 mph, but it will not keep the ratio locked at 50/50.

 

[MightyMo]

The AWD system is controlled by an electro-hydraulic clutch pack in the rear diff (basically an electromagnet that squeezes together a bunch of wet clutch plates).

The ECU can totally vary the amount of lock, from %0 to %100 and everything in between, though of course it can't actually send MORE power to the rear wheels than the front (%100 lock = 50/50 torque split).

Under normal conditions the ECU will only activate the AWD if wheel slip occurs or in some "tight cornersing/braking" situations (I'm really not sure what it means by the latter, but it does say that in the service manual), and it will do this at any speed and any percentage power split it deems appropriate.

Under 19MPH you can manually lock the rear diff (%100 lock, 50/50 torque split). I'm pretty sure the reason for the speed limit is purely safety, high speeds on dry roads with a locked-diff are very dangerous, both from a car control standpoint and for the health of your equipment.

Usually I use the AWD Lock only when off pavement to provide more consistent handling when under 20MPH and preventing getting stuck. I've also used it in the rain around town because I get really annoyed at one front tire spinning for a fraction of a second when I take off from every stop light. Damn VQ35 torque...

It really wouldn't be that hard to feed the AWD system a trickle of current to give 10-20% lock at all times to make the feel more consistant, but I'm not ready yet to be the guinnepig for that test .

 

[zebelkhan]

Usually I use the AWD Lock only when off pavement to provide more consistent handling when under 20MPH and prevent getting stuck. I've also used it in the rain around town because I get really annoyed at one front tire spinning for a fraction of a second when I take off from every stop light. Damn VQ35 torque...

Isn't it true that MO does not have positraction differentials so power gets ditributed to the wheel with less resistance? That means you can spin one wheel in the front and one wheel in the back and/or easily get stuck if one wheel on each end of the car loses traction.

 

[MightyMo]

Correct, front and rear diffs are "open".

If you do a forum search you'll find way back when somebody who parked on a hill with two wheels off the pavement in the snow, put the tranny in Park, didn't use the e-brake, got out and started to walk away...

What then happened next of course is his Mo rolled down the hill on it's own. Park may have locked the tranny from turning, but the weight of the car with the open diffs spun the tires in the snow BACKWARDS

 

[EasternPA]

So the tires spun forward while the car slid backwards down the hill?

 

[Empz]

<sigh>

I have the SL flavour of the MO ...

I don't have VDC or TSC ... all I have is the AWD!

So I guess what I'm experiencing is NOT the VDC ... its simply fishtailing like my FWD Maxima.

The MO just doesn't have the AWD / 4WD feel that my Pathfinder gives me ... or in my friends CRV or Subaru!

 

[MightyMo]

Yes, the tires on the right spun forwards while the tires on the left (and the Mo) went backwards down the hill.

The Murano's AWD is definitly a "get unstuck" AWD system, not a full time system like Subaru. From Nissan's perspective this is a good thing, it's lighter, simpler, cheaper, and provides better gas mileage. From your perspective though, if you weren't aware of this and were expecting the driving feel of a true full time AWD system I could certainly understand your being disappointed.

As I mentioned before, it would be really easy to build an adjustable AWD Clutch lock-up circuit, with a little knob somewhere on the dash to adjust the minimum lock (kinda like on the Subaru WRX STI). Setting it to always give you at least %10 or %20 should give the feel of a full time AWD system, but lord knows if it'll prematurely fry your AWD Clutch (at least until somebody tries it).

 

[Snowride]

The murano on the hill obviously did not have the traction control option or this never would have happened.