Quadro

The critical ingredient missing on RX (and present on GX/LX) seems to be the lack of limited slip differential (TORSEN) and without it you will easily get the experience that OP had.

First of all, without center diff lock engaged, you will go nowhere if only one wheel does not have traction because that's where all the power will go.

With the center lock diff engaged, the power should be distributed equally between front and rear. However, if the front wheels have little traction they can get enough power to spin while the back wheels do not yet get sufficient power to either spin or move the car forward. As others suggested, disabling TC and giving it more power should have allowed the back wheels to either spin or move the car forward.

If you have center diff. locked but one wheel in front and one wheel at the back have no traction you will not go anywhere either.

vlad_a

Actually, TORSEN diff will work the same way as an open diff if one of the wheels has no traction.
It reroutes X amount of torque from one wheel to the other. If one wheel is spinning freely, it has 0 * X to transfer.
That's why on Hummers, it is recommended to press the brake pedal to get some torque transfer when stuck.

Now, the LSD functionality can be logically implemented with the use of ABS. VDIM claims to have this capability.

Quadro

This is correct, however, on GX and LX that problem is solved by using A-TRAC, where the brakes will be applied to the wheel which has no traction thus allowing the wheel which have real traction to keep moving. I guess I should have added that the lack of A-TRACK AND TORSEN is what gets RX into the situation described by OP.

vlad_a

The GX and LX are true 4x4 vehicles, full time at that too. Both are on a frame platform with rear bias.
RX is AWD, where the rear wheels are engaged on-demand and is not capable of transferring all of torque to the rear. Most of its weight is in the front too, making it a poor choice for off-roading. I used to own an old 4-Runner 4x4 which had no electronic aids, other than ABS. It had no LSD or locking diff. My RX450h (VDIM-equipped) doesn't hold a candle to what the 4-Runner could do. The deeper the snow, the better it drove.

However, RX does just fine in the normal snow conditions. The OP may have an actual issue that needs to be investigated. Now, if the tires are bad, no type of drivetrain or electronics can overcome laws of physics.

Quadro

I'm perfectly aware what GX can do because I own one. I also had a vehicle similar to RX AWD before and know how it behaves as well.

GoGiantsNJ

My '12 RX-awd with the 19' Michelins has been one of the better Suv's in snow that I've owned. My old 2000 Subaru Forester with a stick and studded snows went through snow in Maine like a tank.
My old 2004 Saturn Vue awd was the worst in snow.

Quadro

The system works just fine as long as all 4 wheels have something to grab onto which is probably what most people will ever need.

The situation becomes dicey when you start completely loosing traction at some of the wheels. Imagine driving on top of the frozen snow where you have a layer of crust on top with a layer of soft snow underneath. If one of your wheels falls through that would be the end of your movement for now because the entire system acts like an open diff and all the torque will go to the wheel with the least resistance - the one which is now pretty much hanging in he air! I had a friend with AWD Infinity who got into exactly this situation and he had to call for a tow truck! He had no locking diffs. However, the system has to work that way otherwise how you're supposed to drive on pavement?

Now with one wheel hanging in the air you can still lock the center diff and get half of the torque go to each side of the car and that should get you moving as long as the other two wheels have enough traction to get you out. If you have at least one wheel hanging in the air on both sides of your car you're now stuck for good because you still have an open diff at each "axle". Car systems are becoming smarter with applying brakes to wheels without grip thus creating artificial traction and allowing the other wheel to start moving but I do not see Lexus mention anything like that for the RX and it's actually pretty obvious when the car starts braking individual wheels for you (as it happens on GX/LX) just by the sounds of it.

LexRexBlue

I found the RX400h awd system quirky on slick and snowy roads. I was used to the old 300 awd. I hated skidding forward when I applied the brakes gently. The 350awd has been much more sure footed. During surprise storms including Sandy it has gone through wet deep snow, over tree branches, in water, climbed hills, etc. with no problems.

SteveCraig

Tires, tires, tires.
We're East coast too but a little further North.
Not many people locally without a designated set of Winter tires & a designated set of Summer.
All seasons tend to do many jobs, but not all of them very well.
Even my F150 4X4 is useless in the snow without the right tires. Good set of Winter shoes & it'll go anywhere.

DHarrold

We bought a nice used 2009 RX350 AWD in September, 2013. My wife loves the way the Lexus drives and the plush interior. But we really needed a vehicle that would get us up the street in the Kansas winter. We live at the bottom of a hill on a cul de sac. One of our neighbors must have made an enemy at the city, because it seems our street is the last in town to get plowed. We have been snowed in two to three days at a time the past several winters.

Had 10 inches of snow yesterday and last night. Was excited to give this vehicle a try. Well at 6:30 am after plowing my drive we took off. The vehicle was amazing. Right up the unplowed street with no hesitation, slip, slide or anything. My wife is very happy.

We do have brand new Hankook Ventus tires on the vehicle. I am sure that helps. But our questions about how the RX350 will perform in the snow are all answered.:

tfischer

First, low traffic cul de sacs are always the last to get plowed, unless a county judge or city commissioner lives there. Secondly, almost any AWD or 4WD (I'm still not sure what the difference is) will get you up a snow covered street. Tires, however, make a big difference. On the Lexus, in your climate, you probably want to stay with at least all season tires, as they will retain some softness in the cold, unlike performance tires. I don't know what a Hankook Ventus is, but new tires are always better in the snow than worn tires. I have driven all sorts of Front Wheel, 4 wheel and all wheel drive cars in the snow, including a Jeep Wrangler, and the Lexus RX is as reliable as any of them, and much more comfortable.

wase4711

agree about the county commissioner living on your street; ours lives on ours, and we get a "personal" snow plow truck all the time, and our street always gets extra service early on..

my 2014 rx with AWD performs just fine here; we've gotten 61 inches of snow in chicagoland so far this year, and, have had no issues getting around in unplowed areas. This "snow mode" setting seems to help alot as well...

viperdoc

I live in Colorado and in the last week we have gotten more than foot of snow. I don't have a snowblower yet, and typically I don't have to get my driveway plowed because the winds the accompany most snowstorms don't leave much snow on my driveway. But this last major storm was different- very little wind, but lots of snow, so I had between 8-10 inches of snow completely covering my driveway. The driveway is pretty flat, until the end where it goes up, but it is really long. My F sport had no problem with going right through it, whereas our FWD Honda Odyssey with brand new M/S tires could barely get out. Very different cars, but I didn't expect the F sport to do as well as it did.

I don't expect this to be an off road car. And I don't treat it as such. But I have been very impressed with how well the AWD system works (I have the OEM michelins on it, which aren't rated great in the snow either). The only time I have experienced a slight wheel spin is when I am on a full sheet of ice on an uphill, starting from a full stop.

Browninggo

I'm very pleased with the RXs from Lexus. Our first a '09 never ever had a problem with snow. And now the '14 F-Sport is doing fine. They were/are my wife's daily drivers. Right now we have 2 feet plus on the ground and it has plowed through snow drifts 3'-4' high. I'm very impressed with the RX. I try to spin the tires and that doesn't happen. I owned Ford F-150s 4x4s in the past...I feel safer in the Lexus. Snow has not been a problem with these vehicles.

corradoMR2

Very happy with the RXs I've owned in terms of AWD traction and snow/ground clearance for city use and very light offroad duty, but for me, the Michelins although smooth and quiet on dry pavement, are mediocre in wet and snow. I had the same Latitudes on a prior '09 Venza V6 FWD and the wheels spun very easily on takeoff on wet roads let alone snow/icy roads.