[Scalded Dog]

I live in a snowy, icy, mountain area. Every summer (when it's NOT snowy and icy!), newbs move up here to the mountain. When winter hits, they have questions.

Today I heard the question posed, "Will partially deflating my tires help my snow/ ice traction?"

At first, I scoffed, because, well, who ever heard of that for winter conditions? Of course, off- roaders do this for certain extreme activities, as it can greatly increase the tire's contact patch over rocks or when climbing obstacles. But come on... ice and snow?

But... I got to thinking about it... deflating the tires some WOULD increase the contact patch, and, presumably, increase traction, even in ice and snow.

So... does this idea have some validity?

[MGD]

Makes sense in this chart.

[O.F.]

My $.02 - Similar to mud where a narrower tire will dig you down to solid ground. That's the thinking as I know it anyway. Deeper than that...

http://trucktracks.com/en/

[SSJ455]

I'm sure it is a better idea than putting screws in the tread for added traction.

[DGthe3]

Usually its recommended to go narrower for winter tires, not wider. This is to cut through the snow, rather than ride on top of it. Or at the very least, pack it into something more solid allowing for more bite. Reducing air pressure would make the tire more likely to 'float' on top of the snow, giving it less traction.

On ice or cold pavement, you'd still probably want to have your tires at 'normal' pressure. Thats where you're going to have optimal steering and braking. Remember: safe winter driving isn't about how quickly you can accelerate, its about how well you can avoid hitting things.

[Tenring]

Originally Posted by DGthe3

its about how well you can avoid hitting things.

Yep - that is a fact.

[Mr Twisty]

Letting any amount of air from a summer tire for better winter performance isn't a good idea. Let too much out and hit a pothole, now you have a flat.

"Hey it actually helps! ------- But it's still crap,"

Snow tires are amazing compared to summer tires, siped snow tires are a miracle!

[hrpiii]

Originally Posted by Scalded Dog

So... does this idea have some validity?

As you can see, you really can't 'generalize' that answer. It's not like they make one type of tire. That's like asking, what type of laptop should I buy.

For snow tires, no, they are designed to run at stated pressure.

For summer tires, yes, no and maybe. Is the Summer tire and all-season tire, or true performance tire. Are we talking a dusting or 5+" of snow. Do you have AWD, 4WD, or RWD car/truck.

[Scalded Dog]

Lots of good input... thanks, all.

As hrpiii suggested, it's probably not a question that can be answered, given a thousand variables for every individual and situation. I DO roll my eyes at the question, "When should I chain?", for that same reason... far too many variables to answer the question in a general sense.

(Storytime, kiddos: in these here parts of yonder western mountains, chains are often required--- by law--- for travel in the mountains. California Highway Patrol officers set up stations where passage is only allowed after showing that one's chains are installed. However, the CHP is a GOVERNMENT agency, and thus, not quite the well- oiled machine it claims to be.

A few years ago, during a light snowstorm, CHP set up a chain control station. However, soon the storm blew over, the roads were plowed, the snow melted, and there were only wet roads remaining... but chain control enforcement remained.

It remained that day, and the next. Soon, roads were dry, dusty, and temps were in the 70s. But... chain control remained in effect, and CHP officers were there to enforce it, by Job...

For a week, all mountain residents had to chain their vehicles.

Turns out, at the start of the snowstorm, a CHP commander had issued the chain requirement. However, this was just as he was headed out the door for a week's vacation, and, not being there to LIFT the decree, well, it stood.

And for a week of sunny, dry, warm weather, without a lick of ice, snow, or even moisture on the roads, every sorry motorist on the mountain had to chain up.

Yay, government.)

[ChrisBlair]

I am late to this party. Dammit.

MGD. That chart is great but...how does the tire get to contact the snow? Go someplace where there is fresh snow on the ground. Take a wash bucket and a full beer bottle with you.

Place the bottle on the snow. Note how far the beer bottle sinks.

Now pour that beer from the bottle into the wash bucket and place the bucket onto the snow. Compare how far the bucket sank compared to the beer bottle.

Now imagine that the diameter of the bottom of the bottle and the bottom of your bucket are your contact patches. Which one is more likely to touch pavement? How much more weight might you need to get the bucket to sink as much as the bottle?

[Scrappy Doo]

Originally Posted by ChrisBlair

I am late to this party. Dammit.

MGD. That chart is great but...how does the tire get to contact the snow? Go someplace where there is fresh snow on the ground. Take a wash bucket and a full beer bottle with you.

Place the bottle on the snow. Note how far the beer bottle sinks.

Now pour that beer from the bottle into the wash bucket and place the bucket onto the snow. Compare how far the bucket sank compared to the beer bottle.

Now imagine that the diameter of the bottom of the bottle and the bottom of your bucket are your contact patches. Which one is more likely to touch pavement? How much more weight might you need to get the bucket to sink as much as the bottle?

And then drink the beer and contemplate.

[MuhThugga]

Summer, snow, and all-season tires are made of different rubber compounds that react differently to temperature changes. Summer tires start to lose their functionality once the temps dip into the mid-40s, with the grip characteristics getting exponentially worse as the temperature continues to fall. Deflating your tires may seem like a good idea to gain more contact patch in the snow, but you are putting extra stresses on the sidewalls on top of the other inherent dangers that come with driving on under-inflated tires, as now steering and braking are affected even more than they originally were from the winter conditions.

You really should have a good set of winter wheels and tires, or a good set of all-seasons that have a good snow traction rating if you can't afford a second set of wheels, and keep them properly inflated.

[i2disturbedSS]

Asit was explained to me a narrow tire is better to get through the snow. So less contact patch.

Thats why ppl with a winter set up the tires are narrow and maybe even a smaller rim.

[72MachOne99GT]

Originally Posted by MuhThugga

Summer, snow, and all-season tires are made of different rubber compounds that react differently to temperature changes. Summer tires start to lose their functionality once the temps dip into the mid-40s, with the grip characteristics getting exponentially worse as the temperature continues to fall. Deflating your tires may seem like a good idea to gain more contact patch in the snow, but you are putting extra stresses on the sidewalls on top of the other inherent dangers that come with driving on under-inflated tires, as now steering and braking are affected even more than they originally were from the winter conditions.

You really should have a good set of winter wheels and tires, or a good set of all-seasons that have a good snow traction rating if you can't afford a second set of wheels, and keep them properly inflated.

I spent 6 or 7 winters on a 245 series garbage summer tire with my 99GT. Knew it was bad, but never realized how idiotic I was.

Threw some 225s on a 16" rim a few years back. Beyond night and day. Yea, the smaller width was beneficial, as was the different tread pattern.

The biggest difference is the compound. Even in subzero Temps, a snow tire stays soft like rubber ought to be. A summer tire, and even all seasons at some point, turn into rock hard hockey pucks.