Also, if you remember, much greater traction achieved with radial tires as compared to the old bias ply tires, primarily, IMHO, due to the squat/fat factor where the radial puts more rubber on the road.

 

The only time I've found it beneficial to "air down" is when I drive on the soft beach sand at the outer banks.
In that situation you do want to ride over the sand as there is no firm bottom. Also, in that situation the less tread on the tires the better...

 

I don't know who's telling them that or in what circumstances. Are you saying in all situations the key is to air down, in all circumstances involving snow the key is to air down and who is the party stating to do so?

Why doesn't Firestone offer their "winter" tires in wider than stock configurations, and why do they offer them in narrower than stock configurations. Why can I get a 235/80/17 and a 265/70/17 but I can't get a 315/70/17 Firestone winter tire? Seems the widest Firestone winter tire made for light trucks (i.e., a Super Duty) is only 8" wide (maybe I'm missing one somewhere, but I couldn't find a Blizzak wider than 8.1"). Seems Firestone (I'm only using them because you mentioned them) makes tires taller than stock but not wider than stock when making winter specific tires. Seems counter-intuitive if they are teaching you something when training, but manufacturing something different.

Anyway, again, I've driven in snow since I was 12 or 13 years old. I've built 4x4 specific vehicles, ones that drove *****ty on the road but did great offroad, and my experience is different than yours. I'm not saying you are wrong, I'm saying I'm right, for me and for what I do.

By the way, airing down does more than one thing and it is beneficial in different applications. Airing down allows your suspension to work less (the tire absorbs more of the impact), it improves the ride (the tire absorbs more of the impact), AND it creates a wider footprint (less pressure per square inch doesn't just create a wider footprint, but allows the vehicle to "float" more). Airing down also creates a situation where you may not cut the tire or separate the belts as easily. There are many reasons to air down, some are beneficial in certain situations, but not all reasons work well in snow situations (they may or may not depending on the situation, off road, powder, etc.).

So, why doesn't Firestone make all of their Blizzaks in wide sizes?

 

Yep, I think so!

 

wider is great if you're light enough that you will float over top of the snow, its really great in super deep offroad snow i.e. several feet deep. that is not the scenario on the road. the other issue the poster mentioned is that the temp is frequently very near the freezing/melting point. the weight of the tire rolling over the wet snow compresses it and sqeezes out the water forming a wonderful film to hydroplane on. the fact that this film is on top of the now compacted snow(now its ice), the wider the tire the more easily it will hydroplane. both ski's and skates work because the pressure on the snow surface cause a minute amount of melting, and the water acts as the lube that lets them slide. is wet rubber slippery, try wet runners on waxed lino and tell me how it works for you. if conditions are really cold like 30 below freezing then there is very little if any melt and even polished ice road can have pretty decent traction. yup i have worked a good number of winters in northern Alberta on ice roads, and if you showed up with wide rubber( oh wait you wouldn't have got here, you'd be out in the trees somewheres)they'd start a pool on how many seconds before you bite the ditch

 

Duck, I speak as someone who has logged thousands of hours plowing snow. Please go back and read the posts that Ace has made to help answer the question of snow traction. He has thoughtfully laid out all of the theories of superior traction in snow. Everything he said is 100% correct and has been proven by people who make their living driving in snow.
If you need further proof, go to Letstalksnow.com or plowsite.com and spend a few hours searching the snow traction question. 99% of the plow drivers will agree with Ace, the other 1% will be the know-it-all cowboys who keep tow truck operators busy.
On the other hand your ideas on snow traction are fupped Duck.

 

Wolver, I also have a Jeep Cherokee (31x10.5 BFG AT KO tires and an Old Man Emu suspension). It is a REALLY GOOD winter rig. A 3/4 ton truck will never be as nimble as a Cherokee. But I think you will find that the truck is much more stable in deep slush and choppy snow and that can make for a better driving experience. The Cherokee is light enough that it gets bucked around, whereas the heavy truck will cut a straight line. When you drive the truck just don't expect it to turn and have traction like the Cherokee. Be easy on the throttle and get yourself some better tires.

My first piece of advice to you is to not tell people where you work. I work for a world class engineering company and they don't pay me to represent them on this site, and they certainly would not approve of half my posts. I don't want the company to lose a sale because of my big mouth. Same thing applies to you. Don't come on here and give people a poor impression of Firestone.

Now, let's take a 10K foot view for moment and get away from the confusing details. There are two basic schools of thought on how to drive through snow. The first is to use wide tires and float on top of the snow. The second is to use narrow tires and cut through to traction at the ground. Each has a place.

I've never researched arctic exploration but I'm pretty sure that you want to stay on top of the snow because breaking through the surface is death. Low ground pressure is key and wide tires are the method. Tires operate with low air pressure to keep the tire pliable to improve off-road traction over the rough terrain and to lower the contact pressure with the ground.

Again, I've not researched on-road driving but I'm pretty sure you want to get those tires down to the beautifully maintained road surface. Our government seems to agree since they spend a lot of money clearing the roads of ice and snow. In this case you want a narrow tire that will cut through the snow and make contact with the road surface where better traction is to be found. If you use an excessively wide tire on winter roads then you will spend a lot of time trying to find traction or digging out of a ditch. The only people that disagree either lack experience or just don't think they look cool without big mudders on the truck.

The middle ground is deep snow on roads. Do you choose to float on top or cut down to the road? It's your choice. If you can actually stay afloat on top of the snow then driving will be easier.... until you reach a maintained road. Then you're back to having your hands full trying to stay out of the ditch. If you run a more narrow tire then you will be fine in most cases. Under more extreme conditions you'll end up trying to push a front tire through the snow and you would benefit from a differential locker so that both front tires drive. Honestly, this will never be of concern to most people unless they live in high snow fall areas AND the roads they drive are not regularly plowed.

So this all begs the question, What tire is too wide? That's where the debate begins. In my opinion, stock tires are fairly narrow in the first place since they were chosen for all around service and fuel economy. Stay close to stock width and focus your time on choosing the right type of tire for the conditions (tread, compounds, traction aids, etc.).

 

Interesting thing I saw recently.... There's not doubt that water on ice makes for slick conditions but we actually don't know exactly why ice is slippery. People on downhill skis don't melt the snow at all. There just isn't enough pressure. One theory is that the ice has a thin layer of of molecules in the boundary layer between solid ice and air where the molecules move more freely causing the slipperyness. Anyway, that's about all I know. Just thought it was interesting.