Rock Trac can be used in on wet pavement

laueddy

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I spent hours reading many diff. forums and posts on PT 4WD. While most who are against using PT 4WD in the rain where the road is wet, those who do PT 4WD seems to have no problem doing it for years.

With that being said. When I come across this sentence "All road surfaces, including wet or snow-covered pavement, sand or gravel", My interpretation is All road surface with the following condition which includes "wet or snow covered pavement/sand/gravel. This statement is used at numbers of Jeep website including Jeep Canada. https://www.jeep.ca/en/4x4basics

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So, I am starting to think that it's quite possible that PT 4WD is actually usable when it's wet and rainy on regular paved roads. For those who know Seattle, we receive a good amount of rain except during the summer.
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PhoenixM3

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I just recall reading that it shouldn’t be used on dry roads.
 

bobzdar

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I spent hours reading many diff. forums and posts on PT 4WD. While most who are against using PT 4WD in the rain where the road is wet, those who do PT 4WD seems to have no problem doing it for years.

With that being said. When I come across this sentence "All road surfaces, including wet or snow-covered pavement, sand or gravel", My interpretation is All road surface with the following condition which includes "wet or snow covered pavement/sand/gravel. This statement is used at numbers of Jeep website including Jeep Canada. https://www.jeep.ca/en/4x4basics

upload_2018-5-16_0-50-40.png


upload_2018-5-16_0-55-27.png


So, I am starting to think that it's quite possible that PT 4WD is actually usable when it's wet and rainy on regular paved roads. For those who know Seattle, we receive a good amount of rain except during the summer.
Sure, I've used it in extremely heavy rain before - like torrential rain with hydroplane risk. I wouldn't bother in a light rain, doesn't really help at all unless you drive like a complete idiot.
 

DanW

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I use it when I need it, which is off road, snow, or a slippery boat ramp. Otherwise, traction control, stability control, and good tires are the best combo for wet roads.
 

WXman

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That's shocking to me, since everybody knows that wet roads still provide a ton of traction and will still damage a four wheel drive system that doesn't have a center differential.

That's the entire reason WHY there is an optional full-time transfer case offered on JL now.

Personally, I will never engage 4-high part time on mine unless the road is totally covered in snow, or I'm off road.
 

johnnymiz

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as long as you don't make really sharp turns, like into a parking space, there is enough scrub to allow you to use 4h in the rain. but it doesn't really help you much anyway, so why use it?
keep in mind, 4wd makes a really big difference ONLY when you are on the gas.
unless you're compression braking, once you take your foot off the gas and put it on the brake, your jeep is pretty much like any other 2wd vehicle...relying on the 4 little contact patches and traction control to keep you on the road.
to test this, try turning off traction control, turning the wheel and hitting the brake in snow in 4wd... i guarantee you slide.. but once you get back on the gas traction returns and you make the turn.
 

Biscuit

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I spent hours reading many diff. forums and posts on PT 4WD. While most who are against using PT 4WD in the rain where the road is wet, those who do PT 4WD seems to have no problem doing it for years.

With that being said. When I come across this sentence "All road surfaces, including wet or snow-covered pavement, sand or gravel", My interpretation is All road surface with the following condition which includes "wet or snow covered pavement/sand/gravel. This statement is used at numbers of Jeep website including Jeep Canada. https://www.jeep.ca/en/4x4basics

upload_2018-5-16_0-50-40.png


upload_2018-5-16_0-55-27.png


So, I am starting to think that it's quite possible that PT 4WD is actually usable when it's wet and rainy on regular paved roads. For those who know Seattle, we receive a good amount of rain except during the summer.
Usable, yes; useful, not in my opinion. Whether you're hydroplaning on a wet road or skating on black ice, it won't matter if you're in 4WD.
 

$uicide$hift

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Usable, yes; useful, not in my opinion. Whether you're hydroplaning on a wet road or skating on black ice, it won't matter if you're in 4WD.
Bingo!

4X4 is for additional traction. If you are loosing traction driving on wet roads during rain slow down.
 

The_Phew

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4WD causes driveline bind if you have anywhere near decent traction. Driveline bind manifests as crippling understeer, which is a good way to end up in a ditch when you try to take a turn, wet/snowy or not. I'd use 4WD on sand, mud, or to help me get unstuck on snow/ice (then back to 2WD once I'm moving again).

But if there is pavement anywhere under your tires, 4WD can get you killed (and/or break something).
 
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laueddy

laueddy

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My 1st car was a FWD, otherwise, all my other cars have been AWD: Jeep WJ w/ Quadra Drive, STi, 997 C4S, and currently M235i xDrive, except for the Jeep, I have snow tires in the winter since they are all on summer tires. I also had a Miata for a few years as a 2nd car. In my experience, AWD wins when it comes driving in the rain &snow. Engine braking with 4 Wheel using lower gear is more stable in the snow when comparing to RWD, when I corner, I can get to the gas sooner, and when launching the car in the rain, it just go.
Now back to the original topic: Here is an article I found which talk about braking distance:
https://www.qld.gov.au/transport/safety/road-safety/driving-safely/stopping-distances/graph
Assume that the data above is accurate, then the traction different between dry and wet is roughly 31% less.

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When comparing using the above chart, then we are looking at 23% less traction in wet, 77% less traction in snow and less than 1/3 amount of traction on ice than dry.

In theory, when the front and rear is split 50/50, the drivetrain has to overcome X amount fraction to rather or not it's dry/wet/snow/ice. We know dry is too much for the drivetrain. The question would be rather or not our drivetrain is designed to withstand the amount of force to overcome wet road? And maybe that amount is sufficient to sustain normal straight line driving with some minor curves, while in the snow, you can go as far as making a U turn?
 
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