4x4 CR-V tested on rollers. What a complete failure!!!
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Same results with many other 4x4 mini-SUVs as well.
re: https://www.youtube.com/watch?v=9cuZYTQLfA0
Guess the only vehicle that passed "true" 4x4 auto traction is the Subaru Forester.
re: https://www.youtube.com/watch?v=9cuZYTQLfA0
Guess the only vehicle that passed "true" 4x4 auto traction is the Subaru Forester.
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Lol, this.
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Just like these idiots doing the videos, AWD is NOT 4wd, do your homework as it makes you look as bad as those people.
FYI looking at how they are doing the test shows exactly how DUMB THEY ARE.
This is not some legitimate test or even remotely close to one.
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1998 CR-V EX 4spd auto "Big Green" completely stock with roof rack and front mud flaps
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The CR-V's 4WD doesn't fully luck up like a truck. It just makes the rear wheels assist the front wheels when needed. Most 4WD cars are like that because they're not meant for a lot of off-road use.
Again: IT IS NOT FOUR WHEEL DRIVE, IT IS ALL WHEEL DRIVE, WHICH IS COMPLETELY DIFFERENT!!!!
There is no such thing as a 4WD CR-V. This is starting to sound like an argument on Monty Python! So - Bring us a shrubbery, and make it a good one!
There is no such thing as a 4WD CR-V. This is starting to sound like an argument on Monty Python! So - Bring us a shrubbery, and make it a good one!
No, it's not full time locked center differential 4WD. We get that. But the idea of AWD is that it should manage to engage the rear wheels when conditions call for it.
On the Honda and Toyota systems, the vehicles are in FWD mode most of the time. The drive shaft to the rear spins, but it is not coupled to the differential itself until needed in the interest of fuel economy and wear. Wheel speed sensors and computer control should monitor front wheel slip and on demand engage the electromagnetic clutch to bring the rear wheels on line. Yes, there will be a delay, but it should eventually work!
I find this result to be disappointing. Granted I'm used to the Subaru system, which like Audi does port some torque to the rears all the time in varying proportions via a transmission tail shaft clutch. Still, I bought my kid a CR-V believing that it would do what it's supposed to when needed.
So what am I missing? How is this video false? What conditions would satisfy the computer monitoring system and engage the rear diffy clutch??
On the Honda and Toyota systems, the vehicles are in FWD mode most of the time. The drive shaft to the rear spins, but it is not coupled to the differential itself until needed in the interest of fuel economy and wear. Wheel speed sensors and computer control should monitor front wheel slip and on demand engage the electromagnetic clutch to bring the rear wheels on line. Yes, there will be a delay, but it should eventually work!
I find this result to be disappointing. Granted I'm used to the Subaru system, which like Audi does port some torque to the rears all the time in varying proportions via a transmission tail shaft clutch. Still, I bought my kid a CR-V believing that it would do what it's supposed to when needed.
So what am I missing? How is this video false? What conditions would satisfy the computer monitoring system and engage the rear diffy clutch??
Can you explain then why the CX-5 has no issue with passing this test? You seem to be implying that only 4WD vehicles are able to.
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It's NOT a 5th generation CR-V, the 5th Gen. has much more control over the AWD system.
I realize that this does not help those of you whom have Gen. 1-4 CRV's...
(CR-V's owned: '97, '05 EX, '14 EXL, '18 Touring)
I realize that this does not help those of you whom have Gen. 1-4 CRV's...
(CR-V's owned: '97, '05 EX, '14 EXL, '18 Touring)
Indeed!
It would be more appropriate to say it is a dynamic traction assist system where the rear wheels will provide an automatically adjusting tracking assist to the front wheels when the car detects a need to do so. Now.. the vehicle in question here is not a Gen 5... but if it was you can actually use your DII on your instrument panel and call up the screen to monitor traction on the AWD system. It is interesting to watch it for example when you accelerate from a stop at an intersection. You will see the rear wheels apply selective traction to assist the front wheels until you reach speed and ease up on the accelerator. I would imagine that on slippery road conditions would would see the various wheels adjust traction levels dynamically to keep the road conditions safe for the driver as well.
The point being... as others have stated AWD =/= 4WD as classically understood in the case of true 4WD vehicles like Jeep or other true off road vehicles. AWD in the CRV is meant to make street driving or driving on unimproved roads safer then just front wheel drive.
williamsji.
I like your post. And, can relate to it...
My son's AWD labeled 2017 SUV vehicle has a true "full locked" 4x4 system - even though it has AWD label on its outside. Great when pulling / driving out of ice road ditches. But, being full 4x4 lock system, it self destroys itself on too much dry pavement usage. Its so bad, their User Manual clearly states not to engage / use AWD on dry pavement. And, yes. Lots of User Complaints from people who manually leave their SUV in AWD mode during ALL winter months and complaining their AWD system needs to be replaced in 3 short years. Ouch!
Long mumblings short.. I wish his "AWD" labeled vehicle was a dynamic sensing system as well. And, auto makers don't use the words AWD or 4x4 so loosely... re: Not all vehicles operate under the same definitions...
I like your post. And, can relate to it...
My son's AWD labeled 2017 SUV vehicle has a true "full locked" 4x4 system - even though it has AWD label on its outside. Great when pulling / driving out of ice road ditches. But, being full 4x4 lock system, it self destroys itself on too much dry pavement usage. Its so bad, their User Manual clearly states not to engage / use AWD on dry pavement. And, yes. Lots of User Complaints from people who manually leave their SUV in AWD mode during ALL winter months and complaining their AWD system needs to be replaced in 3 short years. Ouch!
Long mumblings short.. I wish his "AWD" labeled vehicle was a dynamic sensing system as well. And, auto makers don't use the words AWD or 4x4 so loosely... re: Not all vehicles operate under the same definitions...
Once you have completed your own research to a sufficient degree, you will have answered these questions for yourself. Until then, you still won't understand the answers, which have already been provided.
arn:You are correct. I have already done plenty of research and understand why your blatant statement is false. I was just hoping you would prove me wrong by providing some more of your divine wisdom. Once again, I'm left disappointed.Once you have completed your own research to a sufficient degree, you will have answered these questions for yourself. Until then, you still won't understand the answers, which have already been provided.
Here is a Honda Engineer explaining Honda's 4WD in the Ridgeline and sort of explaining AWD that the CR-V had in 2006.
Gary Flint was the head of the design team for the 2006 Honda Ridgeline and the 2009 Honda Pilot.
There was a lot of discussion - the link to post #150 explains the original 4WD - there is a lot of discussion - Basically the AWD is only on if the front wheels need help getting going and the read axle cannot engage over a pre determined speed - the test on rollers the front wheels are spinning at the same rate so the rear assist is not needed.
https://www.ridgelineownersclub.com...6-ridgeline-vtm-4-explanation-gary-flint.html
Gary Flint was the head of the design team for the 2006 Honda Ridgeline and the 2009 Honda Pilot.
There was a lot of discussion - the link to post #150 explains the original 4WD - there is a lot of discussion - Basically the AWD is only on if the front wheels need help getting going and the read axle cannot engage over a pre determined speed - the test on rollers the front wheels are spinning at the same rate so the rear assist is not needed.
https://www.ridgelineownersclub.com...6-ridgeline-vtm-4-explanation-gary-flint.html
I have made no false statement, and I am not responsible for your intellectual or emotional well-being. But I do wish you all the best in your endeavor to persevere.
Meanwhile, my AWD is working just fine.
It's kind of funny, really, but I find that those that simply dismiss questions without offering any real help are usually those that CANNOT answer the question. Those that are asking an honest question are being gaslighted....
In #9 (page 1) I described the basic architecture of the system and my surprise that it didn't perform better.
To render an informed engineering opinion, I went back to Honda's own literature. As this is a Gen-4 page and the vehicle in the video is a Gen-4, let’s dive into the Gen-4 fact book. Honda describes the system in use on the Gen-4 as Real Time AWD with Intelligent Control System™. They state that it’s not as dynamic and advanced as the Intelligent Variable Torque Management™ (i-VTM4™) system used on the larger vehicles, but this system works perfectly for small to midsize SUV models. That’s your first tip-off to not expect miracles.
The electronically controlled all-wheel-drive system replaces the previous-generation (Gen-3) CR-V's Real Time 4WD™, a hydraulically activated "dual-pump" system. Compared to the prior system, the electronically activated system offers a faster, more intuitive initial response when a loss of traction is detected.
The capabilities of the system are prioritized to further support high fuel efficiency and all-around drivability on-road as well as off-road. Assisting the front wheels when it is beneficial, Real Time AWD instantly powers the rear wheels when starting from a stop, even on dry pavement, working in cooperation with Vehicle Stability Assist (VSA) and the new Motion-Adaptive Electric Power Steering (EPS). For comparison, the previous-generation Real Time 4WD was designed to allow the front wheels to slip a small degree before torque was transferred to the rear wheels and its primary benefit was at low speeds. Plus, it did not interact with VSA. The new Real Time AWD system can operate at all speeds when needed. The CR-V's all-wheel drive system's major components consist of the conventional front-wheel-drive system, a compact transfer case that distributes torque to a propeller shaft running the length of the vehicle, the rear differential, a new electronically-controlled hydraulic pump, a multi-plate clutch, and left and right rear-wheel driveshafts.
So right off the bat, there's an expectation of some torque to the rears almost all the time, albeit pretty limited. You shouldn't have to wait for the fronts to spin before getting some benefit of AWD.
The previous-generation Real Time 4WD system was mechanically actuated using a pair of hydraulic pumps (one driven by the front wheels and one driven by the rear wheels) along with a ball cam mechanism to operate the clutch that sent power to the rear wheels. If the front wheels began to turn faster than the rear wheels, as would be the case if they were spinning on snow or ice, the difference in pressure between the two pumps would cause the clutch to be engaged, sending power to the rear wheels. The ball cam mechanism was designed to help speed engagement. The system was designed to react to front wheelspin quickly and then send a portion of the vehicle's power to the rear wheels.
Old system: front wheels spinning freely on zero traction surface (ice, or the rollers) should send torque to the rears. I also now understand the term "Dual Pump Fluid" on the quart bottles!
The new Real Time AWD still uses a multi-plate clutch, similar to the clutches used in Honda automatic transmissions, to connect the propeller shaft to the rear differential. But in place of the twin hydraulic pumps and ball cam mechanism used previously, the system now uses an electric motor driving a single hydraulic pump, which operates the clutch. The electric motor is controlled by the Intelligent Control System, which means that the system can actively apportion power based on the conditions. The system doesn't merely react to front wheelspin; it minimizes wheelspin before it happens by sending power to the rear wheels accordingly.
When starting on snow for example, the system sends power to the rear wheels right from the start, minimizing the potential for front wheelspin. The system can also detect when the CR-V is climbing a hill and send a greater amount of power to the rear wheels in cooperation with the newly added Hill Start Assist feature. Hill Start Assist maintains brake pressure briefly after the brake pedal is released, giving the driver time to accelerate and smoothly resume motion. The Intelligent Control System instantly assesses the road's slope angle using a G-sensor and the level of grip as detected by VSA in case of wheel spin, allowing added initial apportioning of torque to the rear wheels for smooth starts.
New system: Proactive, not just reactive! It should respond faster and with the intelligence of using the VSA data and interaction to control wheel slip through active torque management. And it has a slope sensor! So we see a few things at play here. The combo of VSA and RT-AWD should have minimized free spinning of the front wheels by applying some brake force and apportioning torque to the rears. Why isn’t that working?
To answer some questions:
1) Are the rears engaging at all? I think yes, based on the first roller test (F & R one side) where we see the rear wheel start to spin also after a small delay. Active management sends some torque to the rear, and eventually the VSA apportions some torque left to right, and the CR-V moves. So the basics of the system are sound where limited torque transfer is required.
2) What happens when both front wheels spin, such as on a flat road where the fronts are on ice?
a) The roller test is run flat, with very little slope. The G-sensor isn’t detecting a hill, so torque to the rear is limited. You aren't likely to get all that's available.
b) There isn’t a whole lot of max torque available to the rears at best! How do we know that? Let’s peak at the 2017 (Gen-5) data:
The 2017 CR-V is offered with the updated Real Time AWD with Intelligent Control System™. Software and hardware upgrades result in an increase in engine torque (up to a total of 40-percent) that can be sent to the rear wheels, based on the driving conditions. The result is improved performance in low traction conditions when AWD comes into play. Elsewhere we read: For 2017, the maximum hydraulic pressure has been increased, resulting in a 57 percent increase in the available torque transfer to the rear axle.
Interesting.... 40% absolute max, and increase of 57% over the Gen-4 system.... So what’s the MAX rear torque available on a Gen-4? Under 30% under ideal conditions. On basically flat ground with the G-sensor not engaged, it’s probably down to 20%.
And what’s the engine torque on a no-resistance roller set? Unless the VSA is in play to apply some resistance (keeps it in a lower gear and raises engine RPM), engine torque isn’t great. So there isn’t really much to send rearward to help it jump off the rollers.
So maybe part of the question is why the VSA isn’t helping more? I still think, even given the limitation of the system that it should have been able to muster sufficient torque transfer to leave the rollers.
In #9 (page 1) I described the basic architecture of the system and my surprise that it didn't perform better.
To render an informed engineering opinion, I went back to Honda's own literature. As this is a Gen-4 page and the vehicle in the video is a Gen-4, let’s dive into the Gen-4 fact book. Honda describes the system in use on the Gen-4 as Real Time AWD with Intelligent Control System™. They state that it’s not as dynamic and advanced as the Intelligent Variable Torque Management™ (i-VTM4™) system used on the larger vehicles, but this system works perfectly for small to midsize SUV models. That’s your first tip-off to not expect miracles.
The electronically controlled all-wheel-drive system replaces the previous-generation (Gen-3) CR-V's Real Time 4WD™, a hydraulically activated "dual-pump" system. Compared to the prior system, the electronically activated system offers a faster, more intuitive initial response when a loss of traction is detected.
The capabilities of the system are prioritized to further support high fuel efficiency and all-around drivability on-road as well as off-road. Assisting the front wheels when it is beneficial, Real Time AWD instantly powers the rear wheels when starting from a stop, even on dry pavement, working in cooperation with Vehicle Stability Assist (VSA) and the new Motion-Adaptive Electric Power Steering (EPS). For comparison, the previous-generation Real Time 4WD was designed to allow the front wheels to slip a small degree before torque was transferred to the rear wheels and its primary benefit was at low speeds. Plus, it did not interact with VSA. The new Real Time AWD system can operate at all speeds when needed. The CR-V's all-wheel drive system's major components consist of the conventional front-wheel-drive system, a compact transfer case that distributes torque to a propeller shaft running the length of the vehicle, the rear differential, a new electronically-controlled hydraulic pump, a multi-plate clutch, and left and right rear-wheel driveshafts.
So right off the bat, there's an expectation of some torque to the rears almost all the time, albeit pretty limited. You shouldn't have to wait for the fronts to spin before getting some benefit of AWD.
The previous-generation Real Time 4WD system was mechanically actuated using a pair of hydraulic pumps (one driven by the front wheels and one driven by the rear wheels) along with a ball cam mechanism to operate the clutch that sent power to the rear wheels. If the front wheels began to turn faster than the rear wheels, as would be the case if they were spinning on snow or ice, the difference in pressure between the two pumps would cause the clutch to be engaged, sending power to the rear wheels. The ball cam mechanism was designed to help speed engagement. The system was designed to react to front wheelspin quickly and then send a portion of the vehicle's power to the rear wheels.
Old system: front wheels spinning freely on zero traction surface (ice, or the rollers) should send torque to the rears. I also now understand the term "Dual Pump Fluid" on the quart bottles!
The new Real Time AWD still uses a multi-plate clutch, similar to the clutches used in Honda automatic transmissions, to connect the propeller shaft to the rear differential. But in place of the twin hydraulic pumps and ball cam mechanism used previously, the system now uses an electric motor driving a single hydraulic pump, which operates the clutch. The electric motor is controlled by the Intelligent Control System, which means that the system can actively apportion power based on the conditions. The system doesn't merely react to front wheelspin; it minimizes wheelspin before it happens by sending power to the rear wheels accordingly.
When starting on snow for example, the system sends power to the rear wheels right from the start, minimizing the potential for front wheelspin. The system can also detect when the CR-V is climbing a hill and send a greater amount of power to the rear wheels in cooperation with the newly added Hill Start Assist feature. Hill Start Assist maintains brake pressure briefly after the brake pedal is released, giving the driver time to accelerate and smoothly resume motion. The Intelligent Control System instantly assesses the road's slope angle using a G-sensor and the level of grip as detected by VSA in case of wheel spin, allowing added initial apportioning of torque to the rear wheels for smooth starts.
New system: Proactive, not just reactive! It should respond faster and with the intelligence of using the VSA data and interaction to control wheel slip through active torque management. And it has a slope sensor! So we see a few things at play here. The combo of VSA and RT-AWD should have minimized free spinning of the front wheels by applying some brake force and apportioning torque to the rears. Why isn’t that working?
To answer some questions:
1) Are the rears engaging at all? I think yes, based on the first roller test (F & R one side) where we see the rear wheel start to spin also after a small delay. Active management sends some torque to the rear, and eventually the VSA apportions some torque left to right, and the CR-V moves. So the basics of the system are sound where limited torque transfer is required.
2) What happens when both front wheels spin, such as on a flat road where the fronts are on ice?
a) The roller test is run flat, with very little slope. The G-sensor isn’t detecting a hill, so torque to the rear is limited. You aren't likely to get all that's available.
b) There isn’t a whole lot of max torque available to the rears at best! How do we know that? Let’s peak at the 2017 (Gen-5) data:
The 2017 CR-V is offered with the updated Real Time AWD with Intelligent Control System™. Software and hardware upgrades result in an increase in engine torque (up to a total of 40-percent) that can be sent to the rear wheels, based on the driving conditions. The result is improved performance in low traction conditions when AWD comes into play. Elsewhere we read: For 2017, the maximum hydraulic pressure has been increased, resulting in a 57 percent increase in the available torque transfer to the rear axle.
Interesting.... 40% absolute max, and increase of 57% over the Gen-4 system.... So what’s the MAX rear torque available on a Gen-4? Under 30% under ideal conditions. On basically flat ground with the G-sensor not engaged, it’s probably down to 20%.
And what’s the engine torque on a no-resistance roller set? Unless the VSA is in play to apply some resistance (keeps it in a lower gear and raises engine RPM), engine torque isn’t great. So there isn’t really much to send rearward to help it jump off the rollers.
So maybe part of the question is why the VSA isn’t helping more? I still think, even given the limitation of the system that it should have been able to muster sufficient torque transfer to leave the rollers.
4WD is when all the wheels turn at the same speed. Great for low traction situations like mud, snow and ice; not applicable for roads because wheels will want to turn at slightly different speeds, which will wear them and the powertrain out.
AWD allows for the wheels to turn at different speeds with an additional differential. Cheap SUVs apparently use cheap open differentials, which horrendously compromise all of the vehicle when only one wheel is on a slippery patch.
Solution is to use a torque sensing (TORSEN) limited slip differential, which adds about a few hundred dollars to the cost. Apparently both hongdu and toyoma thought it good cost savings to let their cars get stuck all over the place.
These vehicles could be so much more, but without a decent LSD, they are no more than grocery getters for soccer moms, retired school teachers and accountants.
AWD allows for the wheels to turn at different speeds with an additional differential. Cheap SUVs apparently use cheap open differentials, which horrendously compromise all of the vehicle when only one wheel is on a slippery patch.
Solution is to use a torque sensing (TORSEN) limited slip differential, which adds about a few hundred dollars to the cost. Apparently both hongdu and toyoma thought it good cost savings to let their cars get stuck all over the place.
These vehicles could be so much more, but without a decent LSD, they are no more than grocery getters for soccer moms, retired school teachers and accountants.
Setting aside that the test shown is not actually a good test for 4WD on a car that is actually electronically controlled AWD, my understanding is the difference in the case of the CX-5 is that is uses "predictive" dynamic control, whereas the CRV uses "reactive" dynamic control. The CX-5 is not actually 4WD in the classic sense at all (there is no transfer case, and no user control to engage full 4WD).
So.. what exactly is "predictive"dynamic control? Basically a large array of different sensors exist in the CX-5 to sample a range of different conditions and variables and from there try to predict in advance when dynamic traction from the rear wheels is required. An interesting concept and approach, but I have no idea how well it really works in real world conditions. I understand that the additional sensors number in the dozens on the CX-5... and personally... I would not want that for my normal every day driving. We have enough issues with all the electronics subsystems in these newer cars to begin with.. and more sensors and the controllers they feed is just more things to break or get out of calibration and since this involves wheel traction... I see this as overly complex for what is needed in an AWD vehicle.
Honda uses an evolved derivative of it's reactive traction control in it's latest generation AWD vehicles. When it detects any of the wheels slipping, it adjusts individual wheel tracking (and braking) accordingly, and since it adjusts faster then a driver could or would and does so to a specific subroutine it serves it's intended purpose well. It is a simpler system then what Mazda is applying.
As to which approach is better.... I don't think there is a clear answer to that. One could argue that predictive is always a better approach then reactive in closed loop systems, but I'm not convinced in the case of AWD. Both systems are electrical, rather then mechanical, so neither is even remotely a true 4WD. Honda has taken a general approach over time of advancing sophistication of subsystems, particularly safety systems, yet making them simpler in implementation and therefore less prone to errors or problems (such as the TPM sensors now days... Honda monitors the spin of the wheels rather then relying on in-wheel sensors like they used to, which by the way means on rough road conditions the TPM system can and will throw some false positives). I'm sure both AWD systems have plenty of self-checks to figure out if the system is out of whack and needs to have an error light thrown on the dash to alert the driver.
What does predictive mean vs what does reactive mean is the fundamental difference between the Honda and Mazda approaches.
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