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I just read a comment from a former owner of Lexus NX300h AWD, the car which motor and gearbox configuration now is inherited into the new Rav4 Hybrid AWD.
He claimed that e.g. in winter conditions, being stuck in snow and having the front wheels spinning and even if the NX was AWD version, the fronwheels of the Lexus kept on spinning while the rear wheels refused to move at all!

Apparently (and this was his words), Lexus/toyota have made a setup meaning the rear wheels cannot start contributing from stand-still position and need to be in motion for activation.

Seriously? Is this even fair to be called AWD???

I have still one and a half month 'til I get my hands on my own Rav4 Hybrid (I know, Swedish lead times...) and I will surely try it out myself once i have the car in my possession, but for now...could anyone confirm or decline this statement? :confused:

Rob
 

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Discussion Starter #3
2016 RAV4 Limited Hybrid owners manual says to turn off the TRAC in the event of "stuck in snow/mud". Is this where you were headed?
Thanks, but this does not really answer my question. Traction Control is for enabling better behaviour of cars in extreme conditions as slipprey roads, steep manouvering away from dangerous situations etc. This is a function applied on both 2WD and 4WD cars. And when stuck in snow or mud, like the user guide says, the traction control could make the situation worse and therefore it is possible to disengage this function on most vehicles. My question is more for the 4-wheel-behaviour. Actually it is two questions I have: 1. Is this AWD-disengagement-when-rear-wheels-are-at-stop a fact? 2.-Why, if the previous statement is true, has Toyota chosen to disengage AWD in a situation where it is most needed?
 

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The hybrid systems have VERY strict traction control systems, for the simple reason that spinning a wheel can and will cook the electric motor or inverter. The rear wheel drive is all electric, so it stands to reason they won't let you spin the wheels at all. The Prius systems can suffer the same problem, in that with trac control engaged if you lose forward momentum it won't move at all or spin a wheel. Not all models allow you to turn off TC, I can't say whether the RAV4 does but a look at the Highlander system might answer that question. TC works perfectly as long as you are moving and it can take some learning to drive a hybrid on snow/ice. But spinning wheels is strictly forbidden. It can be argued that once forward momentum stops, you weren't going any further anyhow.

No AWD system is perfect.
 

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I suspect the following: the rear motor on the RAV is 50kW or about 67 hp. If the front tires are slipping and the rear tires have enough traction to transfer the full power, depending how stuck you are, that rear electric motor may not be able to move the car making it appear the rear wheels are not doing anything. Also, you may not be getting the full 50kW power based upon how hard the pedal is depressed, battery level, net consumption of the hybrid system and more importantly, electric motors consume the most current when they are stalled, not spinning real fast. The hybrid system most likely reduces the power to the rear motor real quick after it first senses it is stalled and will not move after significant power is applied to prevent the system from overheating or to prevent other damage throughout the electrical power train from occurring, which includes frying the motor. A stalled electric motor is a different beast than a rotating electric motor.
 

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Hoping that Lexus owner didn't switch over to winter tires as that makes a whole lot of difference.
 

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Also, from the manual..Automatically switches from front wheel drive to four-wheel drive (AWD) according to the driving conditions, helping to ensure reliable handling and stability. Examples of conditions where the system will switch to AWD are when cornering, going uphill, starting off or accelerating, and when the road surface is slippery due to snow, rain, etc.
 

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Why would you say this? I am ordering winter tires for my new RAV4 Hybrid. I want to be able to stop in bad conditions - normal tires are like hockey pucks in our winter conditions.

Hoping that Lexus owner didn't switch over to winter tires as that makes a whole lot of difference.
 

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I suspect he means he wishes that NX 300h was on all seasons, as the reason why it failed miserably. We'd hope that it'd do better with winter tires.

However, I'm not convinced it would. If it's stuck in deep snow, the fronts may spin completely freely even with winter tires on. A proper AWD system would engage the rear tires to push it out of the snow, but in this case the AWD system failed to do so. For the record, the Honda CRV (non-hybrid) has the same problem. Or at least it did in one Swedish simulation of the 2014 and 2015 models.

IMO this should not happen, even with an e-AWD system. The fortunate thing is that with the Honda, they were able to correct this behaviour with a firmware update to the AWD control system on the 2014. I'm not saying this is the exact same problem, and indeed it can't be since the Honda system is a traditional mechanical system whereas the RAV4 Hybrid's is a computer controlled separate electric motor, but perhaps the software in neither is designed to take this one outlier situation into account. Usually, the front wheels would have at least weak traction, and in those situations, the rear wheels should kick in.

I call this an outlier situation because I've never been in this situation with any of my three Priuses. Snow here in the city just doesn't get deep enough. I'd probably have to be in the country somewhere on a rough road with 15" of snow or something.
 

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Why would you say this? I am ordering winter tires for my new RAV4 Hybrid. I want to be able to stop in bad conditions - normal tires are like hockey pucks in our winter conditions.
That's exactly what I meant. When the Lexus owner complained about the AWD system, I hope he had not put on winter tires because if he did, I would be very disappointed with the RAV4/NX300H AWD performance. At least it should be as good as a FWD RAV4 when it comes to getting unstuck.

Some people expect an AWD system to be able to do everything a good set of winter tires can in snowy/icy conditions.
 

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Seems it should be good enough on snow but then again one poster confirmed the rear tires don't spin even the front ones are.


Snow And The Nx - Lexus NX300h / NX200t Club - Lexus Owners Club
The nx is good in snow. A lot better than a x5. But the rear wheels never spin even when the front is spinning the rear don't.


Two owners are quite happy so I think the RAV4 Hybrid should perform decently well:

http://www.lexusnxforum.com/forum/9-new-2014-nx-general-discussion-forum/4401-our-nx-mud-wet-snow.html
We have about 1500 miles on our NX 200t. Being used to driving our previous 2011 Outback 3.6R, I've put our new NX in some really challenging situations, just to see how it compares. Today, crawling up a nearly 1 mile driveway of sinking gravel and 4 inches of wet snow, following a new 4WD Tundra, and questioning my intelligence the whole way up the hill... I gotta' say, we went the same route as the Tundra and never skipped a beat! I am soooo freakin impressed with our new AWD NX!!!


Unintentionally I tested the NX thru a ditch & about a foot or 2+ of snow.

Scenario ... I thought the unplowed driveway extended straight out from the garage. NOT! I drove towards the garage door not expecting the ditch. The whole front yard was level with snow over a foot deep. The ditch deeper. Yes, the back wheels got stuck. Sweat. Reverse once, buzz forward and out. No drama at all! There was over 2' of snow in the ditch with 1' over the yard. I "heart" all wheel drive. And I hate the "heart" thing. LOL
 

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Two owners are quite happy so I think the RAV4 Hybrid should perform decently well:

Our NX in mud and wet snow!!! - Lexus NX Forum
We have about 1500 miles on our NX 200t...Today, crawling up a nearly 1 mile driveway of sinking gravel and 4 inches of wet snow, following a new 4WD Tundra, and questioning my intelligence the whole way up the hill... I gotta' say, we went the same route as the Tundra and never skipped a beat! I am soooo freakin impressed with our new AWD NX!!!
How is the NX200t performance relevant to the Rav4 Hybrid? It's a completely different AWD configuration.
 

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How is the NX200t performance relevant to the Rav4 Hybrid? It's a completely different AWD configuration.
LOL, I didn't notice it was talks about the NX200t.

Back to square one and/or people sharing their experience especially after the freak blizzard storm in the US.
 

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Oh, it was the NX200t failing in the mud? Ah I see. Sucks to be turbo then. ;) Hybrid electric is where it's at in the snow then? :)

Still, this should be corrected if Lexus wants to maintain their reputation. Luckily, as the Honda illustrated, this may just require a firmware update.

https://youtu.be/78oMgfeoAfw
300h in the snow, not too bad
Yeah saw that before. Looks decent but they don't really test it in that video.
 
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