yaris cross 4 wheel drive capability

[Yugguy1970]

It's not what I want awd for though, I don't want to go offroading.  I want the car to be able to get its ev instant torque down better on damp public roads, especially when you have to apply the drive while turning the front wheels, e.g. when you do a right turn from a standstill.

I do reckon partially it's the dunlops but even so, awd would help.

[Garth.]

8 minutes ago, Yugguy1970 said:

when you do a right turn from a standstill

And that's one of the problems of Q510 1MM rear motor (and some other to), there's no effective starting torque at standstill and low speed. If movement of vehicle body is not detected, you can't count for much help from the rear. You can see this effect in almost entire UX video and a few times in Rasto Chvala video. 

[Yugguy1970]

1 hour ago, Garth. said:

And that's one of the problems of Q510 1MM rear motor (and some other to), there's no effective starting torque at standstill and low speed. If movement of vehicle body is not detected, you can't count for much help from the rear. You can see this effect in almost entire UX video and a few times in Rasto Chvala video. 

Interesting.  Does the RAV have any modes where you can force all wheels to be driven or is it all computer controlled?  Would it not detect the front wheel spinning, stop it with the ABS and engage the rears?

[Garth.]

@Yugguy1970 Gasoline Rav4 does have the modes, hybrid doesn't. However, hybrid Rav4 has much stronger rear electric motor, its starting torque and max torque is much higher than in Yaris Cross, it can push the car by itself and it is programmed to do that. Traction control doesn't help in front/rear distribution.

 

@Yugguy1970 I forgot to mention - I was talking about current generation of Rav4. Previous generation, despite stronger rear motor, cannot move by rear axle only. Its traction control system is also very ineffective.

[anchorman]

6 hours ago, Yugguy1970 said:

Interesting.  Does the RAV have any modes where you can force all wheels to be driven or is it all computer controlled?  Would it not detect the front wheel spinning, stop it with the ABS and engage the rears?

I can assure you that although on a dry road you don’t see much activity from the rear axle, on a wet road the dash display shows the rear axle working.  I don’t floor the accelerator but I would say “business like” driving coming home from work.  The system is sensitive enough to pick it up and react to it.  None of the wheels slip and there is no TCS activity.  If you ever pas this way you are welcome to come see it.  

[Max_Headroom]

This thread keeps going round in circles.

No one buying the Cross AWD buys it thinking its going to compete with a 4WD it was never meant to and Toyota make no such claims as far as i am aware.

Those that buy the Cross AWD expect it to get them through snow and ice where a 2WD vehicle would struggle and do it with little if any input from the driver.

Does the AWD do that, yes - 

 

 

[Garth.]

1 hour ago, anchorman said:

dash display shows the rear axle working

Sure, but for general information:

On 3/27/2023 at 4:21 PM, Garth. said:

torque applied to the rear axle doesn't mean that wheels spin

Furthermore - it doesn't even mean the car is moving at all.

Dash displays (not only in Yaris Cross but in general) show proportion between the axles, they do not show any values like Nm, any real scale. Proportion may look great but it means nothing if values are poor. Here's the screen from situation when car was stuck, no movement and only one front wheel was spinning:

 

[TonyHSD]

12 hours ago, Max_Headroom said:

This thread keeps going round in circles.

No one buying the Cross AWD buys it thinking its going to compete with a 4WD it was never meant to and Toyota make no such claims as far as i am aware.

Those that buy the Cross AWD expect it to get them through snow and ice where a 2WD vehicle would struggle and do it with little if any input from the driver.

Does the AWD do that, yes - 

 

 

Actually, not. 
The Yaris cross awd has very little benefits over the fwd versions and the help from the rear axle assist it’s only to prolong the time before front axle slips. If this is enough satisfying to the awd owners great, money well worth the upgrade. 👍
However as seen on all videos , once the front wheels lose traction and the car needs more power from the rear axle, the system seems like unable to move the car further and you will get stuck similarly to the fwd cars which question how capable is the awd indeed.

Please note I am only comparing the awd Yaris cross with the fwd Yaris cross, and the difference between both versions, pluses and minuses. 
For example if we compare Audi A4 avant fwd with Audi A4 avant Quattro, the difference between two will be day and night where the difference between Yaris cross awd and fwd is very small. 
No argument, no offence.
Both Yaris version lovely cars. Which one you pick it’s your choice. 
My favourite one is the GR sport. 

[anchorman]

🥱🥱🥱. I know why Terry Wogan left Eurovision for sure.  

[Max_Headroom]

3 hours ago, TonyHSD said:

However as seen on all videos , once the front wheels lose traction and the car needs more power from the rear axle, the system seems like unable to move the car further and you will get stuck similarly to the fwd cars which question how capable is the awd indeed.

The front wheels lost traction as soon as he sets off and half way up the hill but it still makes it up the steep snow covered hill, there is no way a 2wd would have got up there.

 

The guy says "its brutal" and "its great"   as he is driving the car and not watching videos on the internet i think i will take his word for it!

 

 

[Garth.]

1 hour ago, Max_Headroom said:

The front wheels lost traction as soon as he sets off and half way up the hill

Two simple questions, answer them inside your head, just for yourself:

1) do you find it normal that at 28:02 front wheels are spinning forward (traction lost) but the car is rolling backwards with absolutely no reaction from rear axle?

2) do you find it normal that at 46:31 traction control is clicking and only one front wheel is spinning in AWD car?

 

1 hour ago, Max_Headroom said:

he is driving the car and not watching videos on the internet i think i will take his word for it

Didn't you really notice that at 35:50 traction control started to click and a few seconds later he got stuck and couldn't continue? What does he says then, isn't it "No, ooooh..."?

He drove back and then took the whole hill on reverse gear to change to weight distribution. That's a trick you use if you have problems during hill climbing in FWD cars and that's exactly what he did as an experienced driver. FWD car on reverese gear would do exactly the same, there is no deep snow or snowdrift there, just a snowy road.

Rasto says in the video that the system with a wiper motor at the back is much better than he expected but you have to be very carefull with throttle - not to lose to front axle grip. There are the same conclusions in some other tests: as long as car is moving on - everything is fine but if front loses grip and you do not have enough momentum - you're stuck. Here's an example (3:14) of losing grip by only one front wheel (no Trail mode):

 

[TonyHSD]

Correct. 
What I understood from Toyota own videos is that the rear motor is always helping the car from the start. What that means is that the system splits the torque between front axle and rear axle to increase grip, which is brilliant idea and the real benefit from been an awd car.
Fwd cars aren’t suitable for going uphill, the weight of the car moves onto rear axle. The problem here is that the rear motor is small and lacking cooling which is most likely the reason why it can’t cope with extra load when front wheels lose grip. Perhaps next generation Toyota hybrids awd will have more powerful motor and dedicated cooling system which will allow the awd-I compete with conventional awd cars. Prius had similar awd since 2018 and it acts very similarly. 👍

[Max_Headroom]

56 minutes ago, TonyHSD said:

Fwd cars aren’t suitable for going uphill, the weight of the car moves onto rear axle. The problem here is that the rear motor is small and lacking cooling which is most likely the reason why it can’t cope with extra load when front wheels lose grip.

The motor is only engaged when front wheel grip is lost its not running all the time so i don't see why overheating is an issue 

 

 

[anchorman]

59 minutes ago, Max_Headroom said:

The motor is only engaged when front wheel grip is lost its not running all the time so i don't see why overheating is an issue 

 

 

I think you might be wasting your time 😉

[Max_Headroom]

9 hours ago, anchorman said:

I think you might be wasting your time 😉

I think I may have been wasting my time over several pages but I am determined to make the point he has never been in a awd Cross and there is enough evidence from people who have that shows the system does what it is supposed to and that is all owners care about. 

[Garth.]

Rasto Chvala is great Slovakian tester, in Poland there are experienced testers as well, here are their conclusions about AWD-i in Yaris Cross (translated):

PROS:
- when starting on a slippery surface (dirty or wet asphalt) you can feel right away the advantages of AWD-i
- the car accelerates without excessive slippage of the front wheels
- although the all whel drive system itself does not work great, starting from a standstill or entering the corners is much safer
- on a wet surface there is no problem with traction, if necessary, AWD-i system can use the weak rear axle during cornering
- it is not real AWD but it helps on curves much more effectively than the ESP system
- when driving on flat, sandy surface, it is much more efficient than FWD (rear axle resistance is reduced)
- on thin mud it behaves quite correct (surface with not a lot of resistance but enough to transfer the torque by any axle)
- as long as the car is moving, the AWD-i works and the rear wheels spin adequately to the speed of the vehicle, this gives a good effect that the rear wheels are not pulled by the front ones,  it reduces the amount of work the front axle has to do

CONS:
- traction is still poor compared to any other mechanical all wheel drive system
- power of the rear electric motor - too low to spin the wheels properly in many cases
- when a load appears on the rear axle or axle is required to spin cause front axle is not able to transfer the torque - trouble begins
- under load, rear wheels never spin like the front ones
- on sandy surface it works smoothly until there is a real need to power the rear axle
- when the front axle starts to spin/slip, the rear does not - it does not transmit power or the torque is that low that the wheels stop spinning
- when overcoming a sandy hill, the car behaves similarly to FWD
- when the car is standing still and slipping the front wheels, you can't count on the support of the rear axle - it just doesn't work
- too high price of the system in relation to the capabilities (but it's good to have that option as many competitors cars are only FWD)

[TonyHSD]

Weather turns cold and wintery again, an opportunity to test the awd on Yaris cross again. ❄️👌

[Max_Headroom]

6 hours ago, TonyHSD said:

Weather turns cold and wintery again, an opportunity to test the awd on Yaris cross again. ❄️👌

No snow here just a little frost on the screen this morning.

[Alexmouse]

My awd Juke was superb on wet and slippery tarmac, and coped well with snow. My awd Vitara didn't feel as well balanced, and the auto box was slow witted in comparison to the Juke CVT box. I now drive a C-HR and Yaris, both are excellent road cars but do struggle off the line on a wet junction, all that electric torque on just the front wheels. I would be interested to know  how  much a bit of electric traction at the back helps. It pains me to hear those front tyres scrubbing as I try to get away briskly. The new C-HR gets awd but not for the UK, it seems. 

[anchorman]

1 hour ago, Alexmouse said:

My awd Juke was superb on wet and slippery tarmac, and coped well with snow. My awd Vitara didn't feel as well balanced, and the auto box was slow witted in comparison to the Juke CVT box. I now drive a C-HR and Yaris, both are excellent road cars but do struggle off the line on a wet junction, all that electric torque on just the front wheels. I would be interested to know  how  much a bit of electric traction at the back helps. It pains me to hear those front tyres scrubbing as I try to get away briskly. The new C-HR gets awd but not for the UK, it seems. 

I can answer that.  On the little traction plan I never saw a peep from the back wheels on a dry road.  On a wet road, especially up hill, I did see just a couple of bars but no hint of VSC activity.  They’d got the Cross AWD and VSC virtually perfect in my opinion.  By contrast, my current Lexus UX is nowhere near as good although the drivetrain is about to be overhauled to the same system as the Cross.  

[Garth.]

On 1/27/2024 at 11:47 AM, Alexmouse said:

My awd Juke was superb on wet and slippery tarmac, and coped well with snow. My awd Vitara didn't feel as well balanced, and the auto box was slow witted in comparison to the Juke CVT box. I now drive a C-HR and Yaris, both are excellent road cars but do struggle off the line on a wet junction, all that electric torque on just the front wheels. I would be interested to know  how  much a bit of electric traction at the back helps. It pains me to hear those front tyres scrubbing as I try to get away briskly. The new C-HR gets awd but not for the UK, it seems. 

AWD system of Nissan Juke includes torque vectoring on rear axle. There is no conventional open differential (which always splits the torque in 50/50 ratio) but a double clutch pack unit, each rear wheel is powered separately so the torque may be freely shuffled between left and right, for example only to outer wheel while cornering - that's why car feels well balanced.
Similar system may be found in top versions of petrol Rav4.
AWD system of Vitara is quite similar to the one from petrol Yaris Cross, rear axle has open differential which is powered via electromagnetic coupling placed at the end of driveshaft. Automatic gearbox (in petrol) is old-fashioned hydraulic unit.
AWD system of Yaris Cross is described in previous posts, it falls into category of mild awd systems due to speed/torque/power limitations of 1MM electric motor powering conventional rear open diff.
After short research - AWD system of new CH-R is quite similar, it also includes tiny, two shaft type electric rear motor on rear axle but it's 1WM - much more powerful, that is 30 kW/84 Nm (vs  3.9 kW/52 Nm in Yaris Cross).
Gear ratio is the same for both (10.487) but due to better parameters, starting torque of 1WM is probably high enough to push the car by itself, which is huge advantage over the Yaris Cross. It also may have no speed limit of operation.
Video below shows the missing part of Yaris Cross vs Vitara test, it simulates the situation when three wheels have great grip and only one front wheel has low grip. AWD-i system must rely on front axle TC intervention to move the car forward, rear is not pushing enough to prevent the front of losing grip.

 

[Cyker]

Most cars fake a LSD by applying the brake to the slipping wheel, but this is all computer controlled so how effective it is depends largely on how well the software is coded.

I will say I find the traction control in my Mk4 very good - I've had occasions where I've gone round a corner a bit too quick and started to understeer on some loose or degraded surface, and it torque vectors the wheels with the brakes to pull the car round!

For some reason, Toyotas dont tend to do well on these static tests - I have a feeling they rely on the movement sensors that detect slip and yaw angles etc. and without data from them it's not so sure what to do. The cars that seem do the best on those tests are real 4x4s with locking diffs and Subarus  

[Garth.]

1 hour ago, Cyker said:

Most cars fake a LSD by applying the brake to the slipping wheel

Correct but Juke or top versions of Rav4 have real torque vectoring on rear axle, brakes are not involved there. 

And when it comes to brakes - intervention on the slipping wheel is simply a TC. But intervention on non slipping wheel during cornering is a different story, that's not standard function yet. 

 

1 hour ago, Cyker said:

For some reason, Toyotas dont tend to do well on these static tests - I have a feeling they rely on the movement sensors that detect slip and yaw angles etc.

Actually Toyotas are doing well in these tests but not the hybrids, especially those with tiny rear electric motor. 

Majority of other modern awd systems pass these tests, very easily on two rollers, sometimes they struggle on three. 

[152bobby]

On 10/11/2022 at 11:32 AM, anchorman said:

I don’t really know Bob.  I had a Dynamic ordered but I insist on AWD because we do get snow here and they grit the main roads but not the side roads so it can make the difference between getting home or not.  Toyota withdrew the AWD for a short time but then re-offered it as the 2023 Excel but that put me at the back of the queue.  I’ve got absolutely no intention of giving the dealer a hard time because it’s completely out of their hands and Toyota just want to sell cars but it’s out of their hands too.  The supply chains are woeful globally and we can’t blame anyone for it - it’s a legacy of Covid and would you believe, that ship that got stuck in the Suez.  I’m running a newish Yaris which is surprisingly good but it’s not quite big enough and it isn’t AWD or I’d keep that.  I’ve had a 2020 Lexus with Cross Climates on and it was astonishing in the snow.   Because the Cross has not materialised, I’ve just ordered Cross Climates for the Yaris to take me through the winter.  My neighbour bought an AWD and immediately fitted Continental Cross Climates so if the weather turns bad I’ll let you know how that gets on.   Like I said, you don’t just get the driven rear axle you get the proper multi link rear suspension like a small RAV4.  I’ve attached a pdf.  The third photo is after I’d fitted steps but shows the new tyres  

Rear sus parts location.pdf 172.58 kB · 14 downloads

Are the genuine Toyota side steps just a simple bolt on job ? And did Toyota provide a install sheet ? Thanks

[anchorman]

19 minutes ago, 152bobby said:

Are the genuine Toyota side steps just a simple bolt on job ? And did Toyota provide a install sheet ? Thanks

No, it isn’t quite straightforward.  You have to remove the sills to install the mounts and you have to cut the sills to refit them.  It isn’t beyond the wit of man though so if you take your time you’ll be fine.   There’s a whole series of photos somewhere.   All accessory instructions are on the Toyota website.   
 

https://www.toyota-tech.eu/aimuploads/6a66c23c-e2f5-4a38-ab34-112f825b9ed3/Yaris-Cross_Side_Step_PW388_0D000_AIM_006_461_0.pdf