Possible 4WD fault?

[ultralights]

first, about the ICE firing up when under high torque situations, the issue there is with the discharge rate of the battery, output is limited to 60Kw per motor to avoid overheating and damaging the battery due to excessive discharge rates, or the batteries C rating.

and for the trailer, sure, it might be under the max towing capacity of the PHEV, but what about weight of the water in the trailer if its in the water? and the the incline, introduces a rearward component of gravity, effectively adding to the trailers weight, so with these factors, the load could be over the 1500Kg Max rating.

As for traction, an old 4x4 trick is to lower tyre pressures, evenly on all 4 tyres, to increase the tyres contact area on the ground. could be worth a try.

 

[anko]

first, about the ICE firing up when under high torque situations, the issue there is with the discharge rate of the battery, output is limited to 60Kw per motor to avoid overheating and damaging the battery due to excessive discharge rates, or the batteries C rating.

First of all, output is limited to 30 kW per motor (60 kW / 2). But also, keep in mind, high torque situations are not necessarily high power situations. Up to approx. 25 km/h, max torque for both motors require less power than what the battery can provide. But ... if / as long as an e-motor is stalled, losses are at or close to 100%, meaning an awful lot of power is needed to produce just a little bit of torque. When this is the case, how much would firing up the engine help, I ask my self ....

and the the incline, introduces a rearward component of gravity, effectively adding to the trailers weight, so with these factors, the load could be over the 1500Kg Max rating.

This would be something :mrgreen: . The rating is a tow rating, not a pull rating. If the rating says 1500 kg, one can expect the car to be able to pull a 1500 kg trailer up on an incline of at least 12%. I know for a fact that mine manages a 17% incline, while towing a 1500 kg caravan and carrying 4 adults.

Reminds of of my (long ago) Subaru dealer. They suggested I kept the nose-weight of my caravan at 40 kg or less, even though the car was rated for 80 kg, as "I had to factor in the dynamics of driving ..."

 

[ian4x4]

Looking at the video again.

If you look carefully at the gaps above the wheels (and wheel arches) you can see that at first the gaps are more or less equal and the car successfully pull the boat. Then the back goes down and the front comes up and the car stalls.
There is not much weight on that front spinning wheel.

I think the car is probably behaving normally given the drive configuration.

On the Volvo the Haldex Gen 4 or 5 automatic diff is most likely to be set to preload (engage) from standstill up until about 10mph. Hence no front wheel spinning (unless of course a wheel spins on the other axle). Both axles are locked together.

 

[Esparza]

As has been said before is not a power issue but a traction issue. Was the rear left wheel also spining (crossaxle situation)? If not, it has no sense that rear motor doesn't gives enough torque to get out. Did you saw something strange on the S-AWC dashboard?
It seems that at low speed S-AWC needs lot of time to apply mechanical brakes as you can see on this video, will be nice to try same test with the phev.
Maybe keeping your foot down more time solves the problem.
https://www.youtube.com/watch?v=AI9lMky5lUU

 

[ian4x4]

The non-PHEV Outlander is a completely different AWD beast, as explained here. It seems quite sophisticated.

2016 Mitsubishi Outlander S-AWC - Off-Road Review. How does the Mitsubishi AWD system perform off road, in the snow, ice, mud, and gravel? The 2016 Mitsubishi Outlander S-AWC shown features a 2.4L I4 gasoline engine producing 166 HP matched to a CVT transmission. Power can be sent to all four wheels through Mitsubishi's Super-All Wheel Control. The front has an active differential with an electronically activated clutch-type limited slip differential, there's an electronic centre coupler to attach the rear axle, and the rear differential is open but takes advantage of clever braking for torque vectoring.

https://www.youtube.com/watch?v=-D2obMHziNQ

 

[Baingyl]

Thank you all for your hints and ideas, much appreciated.

No reply yet from Mitsubishimotors Sweden regarding any new official towing limits...

However good news is, I was out fishing saturday at a different lake which has a proper boat ramp. I was a little nervous in the evening when pulling out the boat! But as it turned out everything vent perfect. No problem what so ever towing the boat trailer out of the water, that made me very happy. PHEV battery display reported level 1%, which i guess is around 31% in reality.

But as my fishing buddy pointed out, the weight of the trailers front is rather heavy (easily 40kg+) so the next time i am out fishing i will adjust the weight distribution back say 10cm so that there is less weight on the hitch and the back wheels which i suppose also will give less "lifting" on the front wheels causing better overall grip.

Also i will try to get a proper digger vehicle to even out the bumps at the lake where the rear wheels are forced "upward" as seen in the video. The water level in the lake currently is extremely low (lowest for atleast 60years) which makes the "ramp" look very different now compared to early season when i did not have to back out down into the lake as much as i currently need. Perhaps when you take all these combined factors into consideration the limit for what can be expected is reached.

 

[Steepndeep]

Glad to see that it worked out. I found this technical info on the official Mitsu site

http://www.mitsubishi-motors.com/en/spirit/technology/library/s-awc.html

Looking at the pictures it clearly explains that the PHEV only has open diffs in front and rear. And although S-AWC looks good in the marketing material it is clearly inferior to a locking center diff, as e.g. the Volvo has. I would say the marketing of Mitsu borders on a complete lie, at least when you are standstill on a slippery surface and want to take of whith a trailer;-)

If one wheel sits on a very slippery surface then with an open diff that axel is no longer providing ANY forward force. The wheel just spins. And the power of the engine cannot be moved to the rear. So the PHEV is now propelled by one engine at maximum 60kW. Would be nice to see what S-AWC does in this situation as Mitsu claims that the engines shall "follow" each others power, which is exactly what you do not want. You want 100% on the motor with both wheels having traction and you do not care what happens with the other motor. And using the Stability Controlsystem to break the spinning wheel may work, but I have never seen a system that makes this work in practice from standstill.

Well come winter we will have plenty of time to test this in the Scandinavian countries.

 

[anko]

Glad to see that it worked out. I found this technical info on the official Mitsu site

http://www.mitsubishi-motors.com/en/spirit/technology/library/s-awc.html

Looking at the pictures it clearly explains that the PHEV only has open diffs in front and rear. And although S-AWC looks good in the marketing material it is clearly inferior to a locking center diff, as e.g. the Volvo has. I would say the marketing of Mitsu borders on a complete lie, at least when you are standstill on a slippery surface and want to take of whith a trailer;-)

If one wheel sits on a very slippery surface then with an open diff that axel is no longer providing ANY forward force. The wheel just spins. And the power of the engine cannot be moved to the rear. So the PHEV is now propelled by one engine at maximum 60kW.

With all due respect, you sound a bit sceptical :lol:

You state that when one wheel spins the power of the motor on that axle is lost. But why would it be? If that wheel is stopped by means of applying the brakes, the full power of the E-motor on that axle will go to the other wheel on the same axle, wouldn't it?. The only issue is see is that an additional 1:2 gear ratio is added, resulting in reducing the amount of pulling force 'at the wheels' by 50%.

 

[anko]

But as my fishing buddy pointed out, the weight of the trailers front is rather heavy (easily 40kg+) so the next time i am out fishing i will adjust the weight distribution back say 10cm so that there is less weight on the hitch and the back wheels which i suppose also will give less "lifting" on the front wheels causing better overall grip.

I can see how that move would improve the performance on the boat ramp. But don't forget, reducing nose weight means reducing trailer stability. Personally, I would consider 40 kg nose weight on a 1000 kg trailer very little and close to dangerous. May I suggest you move the boat forwards again (and maybe even a little bit more) once you have mastered the ramp?

BTW: With my 1500 kg caravan, I keep my nose weight between 80 - 90 kg, but only because my Dutch PHEV is not rated for more than that.

 

[HHL]

But as my fishing buddy pointed out, the weight of the trailers front is rather heavy (easily 40kg+) so the next time i am out fishing i will adjust the weight distribution back say 10cm so that there is less weight on the hitch and the back wheels which i suppose also will give less "lifting" on the front wheels causing better overall grip.

I can see how that move would improve the performance on the boat ramp. But don't forget, reducing nose weight means reducing trailer stability. Personally, I would consider 40 kg nose weight on a 1000 kg trailer very little and close to dangerous. May I suggest you move the boat forwards again (and maybe even a little bit more) once you have mastered the ramp?

BTW: With my 1500 kg caravan, I keep my nose weight between 80 - 90 kg, but only because my Dutch PHEV is not rated for more than that.

That's odd. The Australian specification is max ball weight of 150kg.
That also matches with the common recommendation of the nose weight being about 10% of total trailer mass.

 

[anko]

That's odd. The Australian specification is max ball weight of 150kg.
That also matches with the common recommendation of the nose weight being about 10% of total trailer mass.

Isn't there some sort of weight distribution system on Australian trailer couplings that transfers some of the weight to the front axle of the towing vehicle?

 

[jaapv]

I fail to see how that would work. Even if the fixing point were on the front bumper, the arm of the fulcrum would be proportionally longer.

 

[anko]

Like this:

http://www.equalizerhitch.com/About%20Equal-i-zer/weightdistribution.php

Come to think of it, it might actually help pulling the boat trailer up the ramp, as it puts more weight on the front axle :mrgreen:

 

[jaapv]

I see, it kind of stiffens up the connection, preventing (flexibly I suppose, otherwise one could not drive through a dip) the sagging of the towing point.

 

[HHL]

That's odd. The Australian specification is max ball weight of 150kg.
That also matches with the common recommendation of the nose weight being about 10% of total trailer mass.

Isn't there some sort of weight distribution system on Australian trailer couplings that transfers some of the weight to the front axle of the towing vehicle?

No. In fact, I have read somewhere that it is not recommended to use on the PHEV.
They are quite common here on the larger rigs, but not a standard requirement.
They can apparently put some weird stresses on the drawbar if not correctly adjusted.

 

[ian4x4]

That's odd. The Australian specification is max ball weight of 150kg.
That also matches with the common recommendation of the nose weight being about 10% of total trailer mass.

Isn't there some sort of weight distribution system on Australian trailer couplings that transfers some of the weight to the front axle of the towing vehicle?

From what I can see, the weight is being transferred backwards onto the trailer wheels, not forwards onto the front wheels.
Therefore less real driven traction.

Seems to be recommended for anti sway and stability, although it looks as if tow hitch needs to be of a special kind, and may not always work with over-run braking.

This forum gets more and more interesting.

 

[anko]

Little bit off topic, but this morning I ran into a video showing the installation of a weight distribution system:

https://www.youtube.com/watch?v=qnO_9hd5SA0

 

[zzcoopej]

From what I can see, the weight is being transferred backwards onto the trailer wheels, not forwards onto the front wheels.
Therefore less real driven traction.

Seems to be recommended for anti sway and stability, although it looks as if tow hitch needs to be of a special kind, and may not always work with over-run braking.

I have personally used 2 different styles of weight distribution hitches (spring type and chain type) on 2 different cars when towing caravans up to 2500kg tare here in Australia, but neither of the tow vehicles was a PHEV. However it does not matter. The WDH definitely transfers weight from the tow vehicles back wheels to the front wheels. You could physically see it in the ride height at the front, and feel the car better planted when driving. The effect was more pronounced on my Subaru Forester than it was on my 100 Series Landcruiser so I would imagine the PHEV would be similar to the Forester.

I believe the simple suggestion on this thread of having someone or something heavy in the back of the boat when coming up the ramp would be very helpful. The driving style of the PHEV and Volvo owners could also be questioned, also the starting or takeoff position of the boat for both tests as I assume one took over where the other left off or was the boat backed back into the water for the 2nd test? In many years of 4wding, I have found that car setup and driver technique often plays a greater part than vehicle capability, until hard limits such as ground clearance and engine power are reached. Was the tyre pressure in the PHEV 38psi or more like most EV owners run to get best mpg?
I was once part of a 4wd group on the soft sand of Stockton beach near Newcastle NSW Australia, and we all had great fun testing the limits of our "real" 4wd. Then, out of nowhere barreled a 2wd Sigma car, doing all the things we had just been impressed our 4wd could "manage". The owners stopped so we asked how they did it. Well, they welded the diff giving true 2wd, had about 10psi in the tyres and drove the car like the $2k wreck that it was - hard and fast. Many lessons learned right there, especially overly careful driving of $100k SUV owners!

One other thing, a starting "jerk" can be achieved with the PHEV by chocking the trailer from rolling back and then disconnecting it from the PHEV. Connect the trailer and PHEV via a "snatch strap" (do you have those in Europe?) which has the MASSIVE advantage of also relocating the tow vehicle away from the ditch the tyre is spinning in. Obviously you do need to ensure the jockey wheel is not going into the ditch or somehow else get broken, alternatively you can rest the towhitch of trailer on a log so it rolls.

That's a dry riverbed we're camped on, not a road. It was about here https://goo.gl/maps/Hs1sjLM7GL72

 

[Phevy]

That's odd. The Australian specification is max ball weight of 150kg.
That also matches with the common recommendation of the nose weight being about 10% of total trailer mass.

Isn't there some sort of weight distribution system on Australian trailer couplings that transfers some of the weight to the front axle of the towing vehicle?

No. In fact, I have read somewhere that it is not recommended to use on the PHEV.
They are quite common here on the larger rigs, but not a standard requirement.
They can apparently put some weird stresses on the drawbar if not correctly adjusted.

Sorry for reviving this threat, but I'm still researching the towing with the PHEV now it has landed in Canada and I'm disappointed to learn that the rating is 1500 lbs i.s.o. 1500 kg.
In Australia it is rated for 1500 kg and 150 kg TW.
Particularly why is the TW double that of the Canadian PHEV :?:
My 1140 kg trailer has a TW of 120 kg and with the construction there is not much to reduce that.
So I was thinking of a weight distribution hitch, but that seems no option.
So I'm wondering what is different with the Australian PHEV?
Anyone knows? :?:

Found this current treat: http://www.myoutlanderphev.com/forum/viewtopic.php?f=10&t=3467&p=40531#p40531

 

[anko]

Why not stick to one thread for your quest? It is certainly not related to this topic ...