Honda 4x4s... not actually 4x4
Discussion
Lozw86 said:
Surely no one buys these to go off road anyway
No. But people would be expecting them to have some degree of getting about in wintery conditions.If you had spent a large amount on what you expect to be a 4x4, and it sat there looking stupid with wheels spinning. You would be rather annoyed.
Yes, winter tyres, blah blah, driver training, blah blah, i can get through 20ft drifts of snow with a 1 series with 1.7mm of tread, blah blah.
The great unwashed will not do the above, so no point trying to talk down that route.
Sheepshanks said:
Colleague in Germany has a Q5 and he said it's spectacularly useless if he doesn't get the winter tyres on quick enough.
Comparing a Disco3 and a Q5, both on 'all-weather' (non-winter) tyres - the Q5 was hopeless up a snowy hill, where the Disco3 barely spun a wheel.brickwall said:
Comparing a Disco3 and a Q5, both on 'all-weather' (non-winter) tyres - the Q5 was hopeless up a snowy hill, where the Disco3 barely spun a wheel.My X5 all season non-winter M+S tyres was pretty much unstoppable on snowy hilly roads. I mean, in a good way!
jep said:
Apparently Honda UK have responded....
I think I'm gonna stick with my Land Rover, thanks....
This explanation is garbage, actually.Honda UK said:
Honda’s AWD system uses a compact, lightweight and fuel efficient rear differential. Due to this construction, certain torque limits are set to enable the unit to perform effectively in real world conditions, while not exceeding the overall strength of the unit.
In real world conditions, regardless of the surface, some amount of friction is available to both front and rear wheels. The AWD system allocates driving torque to the front and rear wheels in order to achieve the best possible driving force, whilst keeping within the torque limits of the rear differential.
In the roller test shown this time, the front wheels have zero friction and the rear wheels have unlimited grip, therefore if all available torque required to move the vehicle uphill was transferred to the rear differential, the torque limit of the unit would be exceeded. Because the torque is limited as described above, the vehicle will not climb the slope in this test condition.
If the vehicle is continued to operate in this condition (front wheels spinning and rear wheels stationary) after some time the system detects high slip and reduces the available torque to the rear wheels to prevent overheating and therefore the vehicle moves back down the slope.
Again, in real world conditions, this situation is highly unlikely. Normally front and rear wheels will be spinning to a similar degree, therefore front or rear slip is small and overheat protection will not be required.
Therefore our opinion is that the CR-V Realtime AWD system performance cannot be verified using this type of test and the result is as expected from the system. However as we demonstrated on 26th March 2013 at Harads together with Teknikens Värld, the actual performance of the system in real world conditions was “very effective”.
I can think of a number of times when I've first moved the car in the snow and my fronts could spin whereas my rears are on snow-free tarmac under the car....In real world conditions, regardless of the surface, some amount of friction is available to both front and rear wheels. The AWD system allocates driving torque to the front and rear wheels in order to achieve the best possible driving force, whilst keeping within the torque limits of the rear differential.
In the roller test shown this time, the front wheels have zero friction and the rear wheels have unlimited grip, therefore if all available torque required to move the vehicle uphill was transferred to the rear differential, the torque limit of the unit would be exceeded. Because the torque is limited as described above, the vehicle will not climb the slope in this test condition.
If the vehicle is continued to operate in this condition (front wheels spinning and rear wheels stationary) after some time the system detects high slip and reduces the available torque to the rear wheels to prevent overheating and therefore the vehicle moves back down the slope.
Again, in real world conditions, this situation is highly unlikely. Normally front and rear wheels will be spinning to a similar degree, therefore front or rear slip is small and overheat protection will not be required.
Therefore our opinion is that the CR-V Realtime AWD system performance cannot be verified using this type of test and the result is as expected from the system. However as we demonstrated on 26th March 2013 at Harads together with Teknikens Värld, the actual performance of the system in real world conditions was “very effective”.
I think I'm gonna stick with my Land Rover, thanks....
If there is front and rear slip then you are screwed and are not going anywhere anyway. Especially with an open diff.
If there is no slip at the rear, your one chance of getting moving, then "software says no" !!
Completely useless.
So Honda are saying that in effect the rear diff will break if it is used to transmit sufficient drive to the rear wheels to get the vehicle moving.
What benefits are there to transmitting less than enough to get moving?
LeoSayer said:
brickwall said:
Comparing a Disco3 and a Q5, both on 'all-weather' (non-winter) tyres - the Q5 was hopeless up a snowy hill, where the Disco3 barely spun a wheel.My X5 all season non-winter M+S tyres was pretty much unstoppable on snowy hilly roads. I mean, in a good way!
- Locking front and centre diffs
- More effective traction control that mimics a locking rear diff
- An ability to send torque to different axles more flexibly than the Q5 (though not sure on this one)
LeoSayer said:
brickwall said:
Comparing a Disco3 and a Q5, both on 'all-weather' (non-winter) tyres - the Q5 was hopeless up a snowy hill, where the Disco3 barely spun a wheel.My X5 all season non-winter M+S tyres was pretty much unstoppable on snowy hilly roads. I mean, in a good way!
the old l200 warrior double cab was bombproof on A/T tyres, electronic rear diff, locked centre diff, i've had it drag itself out of many places with one wheel and towed a few police cars out of the snow when it happened, shame it's an awful car for anything but use on the farm, it did do that well though.
Max_Torque said:
So a "soft roader" like a Honda isn't as good off road in-extremis than say a full sized 4x4, like a defender or whatever. Not entirely news is it.
Now tell me how many actual customers have noticed this "issue"??
A Honda performing less well off road than that same car a year ago is news, at least when the degradation is due to a deliberate OEM effort.Now tell me how many actual customers have noticed this "issue"??
brickwall said:
LeoSayer said:
brickwall said:
Comparing a Disco3 and a Q5, both on 'all-weather' (non-winter) tyres - the Q5 was hopeless up a snowy hill, where the Disco3 barely spun a wheel.My X5 all season non-winter M+S tyres was pretty much unstoppable on snowy hilly roads. I mean, in a good way!
- Locking front and centre diffs
- More effective traction control that mimics a locking rear diff
- An ability to send torque to different axles more flexibly than the Q5 (though not sure on this one)
In terrible conditions (and with hopeless 100% road tyres) I have seen a recent-ish Landie spin all 4 wheels together. Nothing wrong there, only the tyres letting the side down.
To prevent this torque transfer, a' la Honda is just plain crazy, akin to knifing a tyre that is somewhat underinflated!
996TT02 said:
This explanation is garbage, actually.
If there is front and rear slip then you are screwed and are not going anywhere anyway. Especially with an open diff.
If there is no slip at the rear, your one chance of getting moving, then "software says no" !!
Completely useless.
So Honda are saying that in effect the rear diff will break if it is used to transmit sufficient drive to the rear wheels to get the vehicle moving.
What benefits are there to transmitting less than enough to get moving?
The way I understand it any clutch/adaptive AWD system in theory doesn't work with no front drive as there's simply no torque to transfer to the rear wheels, the fronts will just be accelerated with the engine torque instead. Same as if you have an open diff and no friction at all from sheet ice on one side the tyre on that side with no traction will just spin hopelessly and you're going nowhere. If there is front and rear slip then you are screwed and are not going anywhere anyway. Especially with an open diff.
If there is no slip at the rear, your one chance of getting moving, then "software says no" !!
Completely useless.
So Honda are saying that in effect the rear diff will break if it is used to transmit sufficient drive to the rear wheels to get the vehicle moving.
What benefits are there to transmitting less than enough to get moving?
The only 'proper' AWD cars are ones with permanent AWD and locking diffs front and rear.
However in practice car manufacturers use an ECU controlled fake LSD and brake a wheel to avoid the open diff problem. Obviously in this test you've got to brake both front wheels to send torque rearwards and as is suggested perhaps this torque 'spike' isn't allowed by the ECU. This is probably a bug or clever programming from Honda to protect the rear diff from potential damage, but it's interfering in this extreme test.
I know if a tyre gains and loses grip very fast it can be bad for a diff. Even extreme wheelspin/axle tramp can break a standard diff on slicks.
I think it should be easy to update the ECU to get rid of the problem.
996TT02 said:
This explanation is garbage, actually.
If there is front and rear slip then you are screwed and are not going anywhere anyway. Especially with an open diff.
If there is no slip at the rear, your one chance of getting moving, then "software says no" !!
Completely useless.
So Honda are saying that in effect the rear diff will break if it is used to transmit sufficient drive to the rear wheels to get the vehicle moving.
What benefits are there to transmitting less than enough to get moving?
I'm glad someone picked upon that. Aren't they basically saying that to even begin moving it up the incline from purely the rear wheels, the rear differential torque limits will be exceeded!? Is the diff sourced from a lego technic kit? If there is front and rear slip then you are screwed and are not going anywhere anyway. Especially with an open diff.
If there is no slip at the rear, your one chance of getting moving, then "software says no" !!
Completely useless.
So Honda are saying that in effect the rear diff will break if it is used to transmit sufficient drive to the rear wheels to get the vehicle moving.
What benefits are there to transmitting less than enough to get moving?
hondafanatic said:
Why am I a bit of tard? Just out of interest...
They are vehciles designed for on road use that but saddled with the high ground clearance and poor aerodyanmics - i.e. the compormises - associated with a vehcile designed for off-road ability. They aren't in the same league as other vehciles with those similar compromises, either on or off road. To me they are just a fad.
brickwall said:
Not sure of the exact technicalities, but I think the Disco had:
- Locking front and centre diffs
- More effective traction control that mimics a locking rear diff
- An ability to send torque to different axles more flexibly than the Q5 (though not sure on this one)
Pretty much - ignoring the likes of the LR Defender and Jeep Wrangler etc, SUV's like the LR Disco/RR / Jeep GC / Mitsubishi Shogun / Toyota LC and the like have much better 4x4 systems including a low range than the soft-roaders like the X5, Q5/7, X-Trail's etc have. - Locking front and centre diffs
- More effective traction control that mimics a locking rear diff
- An ability to send torque to different axles more flexibly than the Q5 (though not sure on this one)
The Disco and X5 are in a completely different league in terms of ability and aimed at different customers. The X5 is road biased with some basic Trail ability whereas the Disco is far better off-road but not as composed on the tarmac.
Obviously tyres are very important but assuming the same tyres on each, real 4x4's with a low range etc will always be much better off-road that the AWD soft-roaders that have token off-road ability in favour of road-going composure preferred by most who do not need anything that can do serious off-road Trails.
these tests show up specific weaknesses but don't prove crossovers as totally useless. If you live in areas of snow and you're trying to stay ON-road then the extra ground clearance and improved traction is useful (i didn't say faultless or comparable to a Forrester). Combined with car-like characteristics and high position, they're great. Fit for purpose and comfortable. I got a Rav4 just for this reason and it's been great for 6 years. Winter tyres do most of the work but i do seem more agile than 2WD cars in winter. Oh, and it starts first time in -20, so no, i'll pass on LR products.
::taking cover:: I also love its CVT box ;-) (But it's the only car i own with any drive to front wheels)
::taking cover:: I also love its CVT box ;-) (But it's the only car i own with any drive to front wheels)
Edited by Robert Elise on Friday 26th December 19:24
Nothing seems to have fazed the Outback so far, including pulling a Volvo XC90 that was stuck in a lane with compressed and ice like snow. The Volvo couldnt get up a shallow incline, the Outback pulled it up the same incline. Outback was wearing OEM Geolander All Season Tyres, bot sure what the Volvo was wearing.
Gassing Station | General Gassing | Top of Page | What's New | My Stuff