A question for my northern brothers.

Driving on ice and snow isn't something we do a lot down here in the South. The few times I've done it it hasn't been an issue. Snow is like mud. Ice is like wet clay. I've had a fair amount of practice in both so I drive accordingly and have always managed to keep it between the lines or at least on the road surface. 

I run Falkens Wildpeak tires which do have the Three Peak Mountain Snowflake symbol. Understanding they aren't a true winter tire, they have been pretty good on the little bit of snow and ice I've had to deal with. In mud and clay, lower tire pressures make a significant difference in the amount of available traction so I frequently run 18-20 psi for better grip.

My question is, does airing down also work in snow and ice or is that a waste of effort?

This is the Cherokee playing in the Francis Marion NF in 2018. 

Airing down does not work. The tread needs contact to move water out of the way and reducing contact force in the middle o the contact patch is counter productive.

I live where it snows several feet each year, but am relaying the information as explained to me by driving instructors at the Bridgestone Winter Performance driving school.

I've never heard of it. I don't think it would help at all; you're ultimately going to break through any snow and compact it no matter what the pressure is. Additionally, because of phsyics, you'll see some airing down effect in the cold without actually doing it. 

For snow you typically want as skinny a tire as you can get to break through and get to hard ground. Airing down would have the opposite effect. 

matthewmcl said:

Airing down does not work. The tread needs contact to move water out of the way and reducing contact force in the middle o the contact patch is counter productive.

I live where it snows several feet each year, but am relaying the information as explained to me by driving instructors at the Bridgestone Winter Performance driving school.

+1 to this. We have played with this at the proving grounds and saw even worse traction. 

I'll add airing down in deep snow can help, but ice it won't do a thing. 

Depends on how deep.. In very deep snow, sure air down.. but we rarely drive on a foot or more of snow.  So just leave them at normal air pressure for when you do find the actual clear pavement..

Professor_Brap (Forum Supporter) said:

matthewmcl said:

Airing down does not work. The tread needs contact to move water out of the way and reducing contact force in the middle o the contact patch is counter productive.

I live where it snows several feet each year, but am relaying the information as explained to me by driving instructors at the Bridgestone Winter Performance driving school.

+1 to this. We have played with this at the proving grounds and saw even worse traction. 

I'll add airing down in deep snow can help, but ice it won't do a thing. 

Came here to just echo this.  If you're swamped in deep deep POWDERY snow but not high-sided, airing down can help a bit.  But us northerners typically know if you're stuck, it's time for a shovel, sand, a come-a-long, and some exercise.  Especially nowadays when the snow seems wetter, denser, and any wheel spinning just creates an ice patch.  

Whenever I did wheeling trips back in the day we aired down going into snow. Not for ice, but in an attempt to ride on top of the snow. I don't know where the idea came from though? That was always on logging roads though, not street driving.

It works on knobbies, and some race tires, but radials are different.

When I was racing circle track everybody in my (street tire) class was copying the big boys, running low pressures, and were all having handling and tire problems, and chalking it up to racing on street tires. I was running 32-36psi and winning.

Also, to echo the 'airing down is useless in snow' aregument-  most serious plow operators I know in the area run pizza cutters as their winter wheel setup. Tall sidewall, skinny tread.  Gives you ground clearance but without the drag of a large contact path. 

Yes, good snow/winter tires FOR THE ROAD are pizza cutters to maximize pressure on the ground and minimize how much power you need to put down to go through deep snow, and power costs grip.

If you are driving a 4x4 on Arctic terrain, air them down for a snowshoe effect so you do NOT punch through.

Tires lose air in cold climates so 1/2 the 80's Delta 88's you see are already down to 20psi.

When you talk about pizza cutters, it was hard to imagine anything more pizza cutter than the 155s on 19 inch wheels that were the snow tires used on the i3!

Thanks for the info.

I'm hoping to spend a snowy weekend or two in the mountains this winter and figured I'd ask. I'm sure the main roads will probably be clear pretty quickly, but the farm is a good way out of town on a dead end and may be way down the list of roads to get cleared. 

FYI, VW recommended +3psi for winter tires in the owners manual for a 2000 Golf. 

I've always ran more air in winter. I want to make the tire as skinny as I can and act more like a ski in snow. Ice outside of studs I really haven't found any sweet spot besides just slowing down.

What makes tires good on ice is many small sipes while the bigger blocks paddle their way through snow and mud.  

Sipes need to be flexible so they can open while making contact.  This is the reason winter tires are often a soft compound not good for higher ambient temps.  These sipes are also not deep and wear to a shallower depth quickly.  These two factors are often why people say their winter tires are great the first season and noticably less great in subsequent winters.  

Sipes

Sipes in yellow

I have Wildpeaks on my Renegade. Last winter I left them on and they worked fine at their normal pressure.  

Not snow, but in my regular offroading, we pretty much found airing down wasnt beneficial unless you were going to go down to like 2 PSI. That wasnt going to happen unless you had beadlocks and a compressor. 

Pizza cutters......150-160mm section width, with tread width 110-120mm

In the mountains, weather can change quickly.. If you are concerned, I'd grab a set of cheap chains or autosocks from amazon and throw them in my trunk.  $200 for some piece of mind is useful.

something like this..https://www.amazon.com/Security-Chain-SZ343-Passenger-Traction/dp/B002KQG7TK/ref=sr_1_21?crid=KFBE4UVQJOU9&keywords=tire%2Bchains&qid=1701805766&sprefix=tire%2Bchains%2Caps%2C124&sr=8-21&th=1

In reply to Fueled by Caffeine :

That's not a bad idea. 

Haven't read all the replies, so this may have been covered. It depends on if you're on the road vs a trail, and if we're talking about snow pack vs fluffy stuff.

In reply to DrBoost :

Basically talking about whatever might be found. My guess is around town it will be plowed roads with sand and such. The farm is about 40 minutes away from civilization so I assume that as we get farther from town the roads will get worse. I honestly don't know what the conditions will be, I've never been up there during snowy weather. I'm hoping a little knowledge goes a long way to keeping a car out of the creek. 

I think wildpeaks and a smart driver are more than adequate winter prep for the lower 48, assuming it's not a 100 year storm or anything like that.  I'd keep a shovel, comealong, various rigging straps/accessories, and some traction boards if you have easy access and want to overplan, but I think it's probably not going to be needed.  How's cell service in the area?  If it's good, I wouldn't be concerned at all.  

Just use your wits and take it slow.  Power is the enemy of traction in snow, so lugging and crawling is almost always the answer unless you're stuck.  Then all bets are off and use the ponies. 

Ever made a snowball?  That's basically how tires make traction in snow.  Snow packs into the sipes and grips the snow with snow.  The tire itself doesn't have much traction against the powder, so they work by holding it in the voids.  Packed snow grips to other snow very well.  That's also why M/T tires suck in the snow.  The voids are so big that they can't hold the snow.

Airing down the tire will also artificially create a larger contact area which will act like snowshoes and keep you on top.  It will also make less pressure between the contact patch and the snow which will do a poorer job of creating those tightly-packed "snowballs" in the sipes.

The idea of running pizza cutters in snow is that it additionally sinks into the snow and gets closer to the surface underneath.

Ice is ice.  Soft compounds help, but there isn't a magic bullet for ice unless you run studded tires or chains, both of which are ancient technology and (IMO) have no place on the road.