Tire pressures in snow?
#41
JK Super Freak
either way it's off to the trails tomorrow for me on my 33" FirestoneDestinations, weather has warmed up considerably up here to +6C (from -26C a couple weeks ago) and from what I understand about 1.5-2' of snow out there...so the snows gonna be a different composition than the powder I was expecting, we'll see what happens cause I'm not bringing any chains with me...just a bunch of buddies
And yes I definately believe that off road and on road are two different worlds when it comes to tire inflation...definately maintain proper pressure while operating on road...maintains appropriate handling characteristics, reduces heat build up improving tire life, and improves pounds per square inch traction....it's the off road I'm curious about...
#42
This is what I'm thinking as well...I'm thinking it's really situationally dependant....else why would there be so many hardcores on either side of the fence right? If one way simply worked for all conditions I'm pretty sure it would be commonly accepted and never refuted....as it is, we have two schools of thought with good arguments on both sides...
either way it's off to the trails tomorrow for me on my 33" FirestoneDestinations, weather has warmed up considerably up here to +6C (from -26C a couple weeks ago) and from what I understand about 1.5-2' of snow out there...so the snows gonna be a different composition than the powder I was expecting, we'll see what happens cause I'm not bringing any chains with me...just a bunch of buddies
And yes I definately believe that off road and on road are two different worlds when it comes to tire inflation...definately maintain proper pressure while operating on road...maintains appropriate handling characteristics, reduces heat build up improving tire life, and improves pounds per square inch traction....it's the off road I'm curious about...
either way it's off to the trails tomorrow for me on my 33" FirestoneDestinations, weather has warmed up considerably up here to +6C (from -26C a couple weeks ago) and from what I understand about 1.5-2' of snow out there...so the snows gonna be a different composition than the powder I was expecting, we'll see what happens cause I'm not bringing any chains with me...just a bunch of buddies
And yes I definately believe that off road and on road are two different worlds when it comes to tire inflation...definately maintain proper pressure while operating on road...maintains appropriate handling characteristics, reduces heat build up improving tire life, and improves pounds per square inch traction....it's the off road I'm curious about...
Tire inflation in snow is dependant on the kind of snow you will be wheeling in. In hard packed snow air down to minimum PSI to increase Foot print and flotation.
#43
JK Super Freak
I live way up in Northern Quebec (Kuujjuaq) and temperatures in the winter ranges from -20 to -40 from November to March. The snow here is very dry and hard packed almost like concrete. Aired down is the way to go to stay on top of the snow cover. If you start digging into that kind of stuff and get high centered your gonna be stuck for a long long time.
Tire inflation in snow is dependant on the kind of snow you will be wheeling in. In hard packed snow air down to minimum PSI to increase Foot print and flotation.
Tire inflation in snow is dependant on the kind of snow you will be wheeling in. In hard packed snow air down to minimum PSI to increase Foot print and flotation.
#44
I went wheeling yesterday and to get around in the snow I needed to drop to 8 psi with the stock rubi tires and wheels.
If you dug in you were done and needed to be winched or pulled out.
The link is to some picutres of yesterday.
https://www.jk-forum.com/forums/jk-trails-tales-71/west-branch-sno-run-1-17-2009-a-69039/
If you dug in you were done and needed to be winched or pulled out.
The link is to some picutres of yesterday.
https://www.jk-forum.com/forums/jk-trails-tales-71/west-branch-sno-run-1-17-2009-a-69039/
#45
JK Super Freak
There is nothing more fun than breaking trail in the deep snow, but i have a question, after running in the deep snow for a while i lost my brakes. pedal would just go to the floor. after a while they came back and all was fine but quite a shock comming off the trail and onto the hi way. any one else run into this i am sure the rotors and pads are wet but no pedal at all.
#46
There is nothing more fun than breaking trail in the deep snow, but i have a question, after running in the deep snow for a while i lost my brakes. pedal would just go to the floor. after a while they came back and all was fine but quite a shock comming off the trail and onto the hi way. any one else run into this i am sure the rotors and pads are wet but no pedal at all.
It would take a few pumps to get them back were they belong. Just a guess.
#47
JK Super Freak
yea i thought about snow getting between rotors and calipers but it was at least 10 miles on and off the brakes before i started to feel them come back. at first i thought i had busted a line thats how easy the pedal went down.
#48
In the Intermountain West (Montana, Wyoming, Utah, Idaho, Colorado, etc.), for offroad snow wheeling we air down to less than rockcrawling psi for more flotation.
With 33s, it is common to air down to 10-12 psi for rockcrawling and 6-8 psi for snow wheeling.
With 37s it is common to air down to 7-10 psi for rockcrawling and 4-8 psi for snow wheeling.
These psi levels are for offroad use only.
I have never seen someone lose a bead at these psi levels. If there is someone in our group who struggles (constantly needs a tow strap), they are always running too much psi.
The strategy in crusty snow is often to idle over it--at least with a 2 dr on 35s at 6 psi you can drive on top as long as you don't spin your tires and break through the top layers.
The strategy for soft snow is to have the rigs on 40s with lots of horsepower break the trail, followed by the guys on 37s, then the 35s, etc.
Regarding the picture below, the first rig was a 4 Runner on 39s with performance V8 (not in the picture). The rig in the right front of the picture is a 4 Runner on 37s. Then the black TJ is mine on 33s, followed by the yellow Bronco on 35s, etc., etc.
With 33s, it is common to air down to 10-12 psi for rockcrawling and 6-8 psi for snow wheeling.
With 37s it is common to air down to 7-10 psi for rockcrawling and 4-8 psi for snow wheeling.
These psi levels are for offroad use only.
I have never seen someone lose a bead at these psi levels. If there is someone in our group who struggles (constantly needs a tow strap), they are always running too much psi.
The strategy in crusty snow is often to idle over it--at least with a 2 dr on 35s at 6 psi you can drive on top as long as you don't spin your tires and break through the top layers.
The strategy for soft snow is to have the rigs on 40s with lots of horsepower break the trail, followed by the guys on 37s, then the 35s, etc.
Regarding the picture below, the first rig was a 4 Runner on 39s with performance V8 (not in the picture). The rig in the right front of the picture is a 4 Runner on 37s. Then the black TJ is mine on 33s, followed by the yellow Bronco on 35s, etc., etc.
#49
JK Freak
Join Date: Feb 2008
Location: Jacksonville FL / Denver CO
Posts: 615
Likes: 0
Received 0 Likes
on
0 Posts
Some very interesting ideas. I have never really thought about airing down or up as some of you also suggested. Frankly as far as I am concern 2 pairs of Rud grip 4x4, one on each tire will work great in snow or extreme mud.
#50
JK Enthusiast
Join Date: Apr 2007
Location: San Lorenzo CA 94580
Posts: 249
Likes: 0
Received 0 Likes
on
0 Posts
Tires do not 'float' on snow. Nor do they float in water unless they are 50" balloon tires. What make a tire work in snow is 'compaction' If the tire can compact enough snow to support the weight of the vehicle before any of the undercarriage touches, then you will be able to move. A wide tire (made wider by airing down) will compact more snow than a similar skinny tire.