JL Rubi - driving at highway speed on snow/ice/wet with 4H

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And a fair amount of them end up in the ditch.
That they do. I'm sure you see the same thing there in Oregon that we've seen for years in Colorado. Snowy pass and we're coming home from skiing doing maybe 45-60 and people whip by you at 70 or above.





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word302

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That they do. I'm sure you see the same thing there in Oregon that we've seen for years in Colorado. Snowy pass and we're coming home from skiing doing maybe 45-60 and people whip by you at 70 or above.
Yup. What most of the flatlanders don’t realize is that the little Honda Civic passing them is much safer at higher speeds. I would much rather have a small, front-wheel drive vehicle with good tires on the mountain than almost any SUV. I don’t go 60 in the snow. It only takes one jackass spinning into you or a deer jumping out in front of you to ruin your day. Not worth it to save a few minutes.
 
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Yup. What most of the flatlanders don’t realize is that the little Honda Civic passing them is much safer at higher speeds. I would much rather have a small, front-wheel drive vehicle with good tires on the mountain than almost any SUV. I don’t go 60 in the snow. It only takes one jackass spinning into you or a deer jumping out in front of you to ruin your day. Not worth it to save a few minutes.
I don't disagree at all. I'm a physician and have seen my fair share of nightmares roll into the ER from traffic accidents.
 

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Real 4x4 systems aren't "smart". For high speed driving in all conditions, you need a system like you will find in AWD performance cars such as the Subaru WRX. Selec-Trac is great for driving in slippery conditions it is not "smart" though like sophisticated managed systems. Offroading, I've seen selec-trac Jeeps bury their rear wheels when the front had traction and get stuck just as easy as a 2wd. Make sure if you are in actual offroad conditions (trails, etc) that you are in 4-hi lock. Our grand cherokee's selec trac just doesn't react in time for patches of snow on the road.
 

word302

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I don't disagree at all. I'm a physician and have seen my fair share of nightmares roll into the ER from traffic accidents.
Yup. I lived on Mt Hood for a few years after high school. Saw so many idiots get hurt. The only thing you really have control of in low traction driving is time. The only way to give yourself more time is to slow down. If I were the only one on the road, I’d probably go a little faster.
 
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Have you ever lost traction in the snow in a 2WD vehicle due to the application of power at 55mph? If so, having 4WD wouldn't really help much. All 4WD does is send power to both axles in the event that one of them has traction. 55mph is 80ft/s and let's assume a 10ft wheelbase... In that case, it only takes the rear axle 1/8 of a second to reach the traction-rich ground where the front axle used to be.

4WD is for getting you going at low speeds. If you're spinning tires at highway speeds due to power application, you're driving way too fast for conditions and will never be able to brake in time.
 
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Have you ever lost traction in the snow in a 2WD vehicle due to the application of power at 55mph? If so, having 4WD wouldn't really help much. All 4WD does is send power to both axles in the event that one of them has traction. 55mph is 80ft/s and let's assume a 10ft wheelbase... In that case, it only takes the rear axle 1/8 of a second to reach the traction-rich ground where the front axle used to be.

4WD is for getting you going at low speeds. If you're spinning tires at highway speeds due to power application, you're driving way too fast for conditions and will never be able to brake in time.
I disagree. If the road is wet and I have to make a sudden maneuver where I decelerate quickly and then have to accelerate I want to know that all 4 wheels are under power - whether it's 30 mph on snow or 65 mph on a wet interstate. I get that the Rubi system isn't as smart at sensing slippage and applying traction control/braking/power reassignment as a Subaru Outback or LandRover.

I think my question here has been answered.
 

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If I may segue, am I correct that the select-trac is only available with automatic transmission? I am just curious why you couldn't have that system in a manual transmission (similar to Audi, Subaru, etc.).

Thanks,

Jeff
 

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If I may segue, am I correct that the select-trac is only available with automatic transmission? I am just curious why you couldn't have that system in a manual transmission (similar to Audi, Subaru, etc.).

Thanks,

Jeff
My guess is is a cost/benefit issue. They figure the cost associated with the engineering for that option would outweigh the sales.
 

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Nothing about this post I am making factors in a Rubicon locker system. (I did research for my own knowledge and thought I would share)

Part time (aka non Selec-Trac for Jeeps) locks both the front and rear drive shafts together mechanically via the T-case (again nothing to do with Rubicon diff locks). This is specifically designed for off road use, or on road use in instances of slippery conditions where all 4 wheels will not at all times be 100% under power and traction. Any event where binding could occur on solid ground (turning at high speeds or any other condition that could cause a sudden lag in either the front or the rear) can and most likely will result in drive line damage. The higher the speed when the binding occurs means the greater the chances of catastrophic damage occuring.

Full time 4x4 (aka Selec-Trac for Jeeps) can be used at any time, and on any surface condition because the front and rear of the vehicle are not required to turn at the same rate of speed. Although power is being applied to the front and rear (not entirely equally but close enough 40%/60% ish) it does still allow for each axle, and all 4 wheels to turn independent of one another at different speeds. Binding is not an issue, and the drive line will be much happier.
 

maxmk8

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Can we talk about how 4x4 or AWD isn't needed above 30mph period or are we going to chalk that up to "fake news".

If you don't have traction to accelerate above 30mph AWD will not make anything safer. You're just as likely going to end up in a ditch or off the road.

AWD is only good for low speed acceleration during slippery conditions. 70mph+ AWD... ain't nobody doing Ken block style drifting on the freeway.
 

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In a full time 4x4 system I would say if you can go over 45-55mph do you really need to even be in full time 4x4 at that point anymore? Most conditions you may find yourself needing 4x4 Hi I would think would be far too dangerous to consider going over 45-55mph max.

I have done a lot of snow and ice driving the last few days here in VA (which is a lot for us, road crews cant handle and are not prepared for the amount we got out here) so my 4-Hi on the fly has been getting a work out as of late. Once I hit 35mph I throw it back into 2WD regardless of conditions...because if the conditions absolutely require me to stay in 4-Hi...im not going over 35mph anyways.

Highway speed is not an option for me personally if the conditions are such that it warrants the need for full time 4x4
It's not always up to you. Trucks on the trans-Canada slow down for nothing, and it's dangerous for everybody if you aren't moving with traffic.
 

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Would part-time 4H or full-time 4H be superior and more stable to RWD when changing lanes or passing in severe blizzard conditions at highway speeds?
 

maxmk8

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Would part-time 4H or full-time 4H be superior and more stable to RWD when changing lanes or passing in severe blizzard conditions at highway speeds?
Who the hell drives at "highway speeds" during "Severe blizzard" conditions. Unless there is a semantics issue, you're going 20-30mph during said conditions and most def in 4H.
 

maxmk8

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This is driving in a "Blizzard" I don't see how
a) 70mph is safe or in any shape or form possible
b) perfectly illustrates how 4H is perfect for this and it makes the speed "cap" a non issue.
 

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