To snow tire or not to snow tire, das ist kvestion

[Dean]

Here is one useful quote:

Originally Posted by CNN & Michelin Engineer(2002)

In contrast, winter tires are designed with softer rubber compounds that maintain their grip in freezing temperatures. More important, their deep treads are densely packed with small crosshatchings called sipes. Like the edge of a ski, the thousands of tiny sipes carve deeply into the snow to deliver traction. "The name of the game is how many biting edges you can get into the snow," says Ron Margadonna, technical marketing manager for Michelin North America.

[Dean]

Narrow is good for deep snow due to resistance and tendency for the wider tire to plow, but most of us seldom if ever deal with true deep snow as it is as likely to high center many Subaru models and other passenger cars. We deal mostly with plowed roads with packed snow/ice an/or up to 1" of wed/dry snow. These conditions are where siping rules.

[left footed whooten]

Here we go. This is it so long as I can verify that the steelies will fit. Dunlop 3D's 205 55 16 on steelies for $580 mounted & balanced. 24.6" OD vs 24.9" OD. Beats $508 tires only for Revo's in 225 45 17. Tire rack's catalog offers a 15" wheel/snowtire pkg for my car. I doubt its correct, but 15x6's e45 that fit over the 4 pots? I've got to ask on that one. Sound plausible?

[Kevin M]

No, 15s won't clear 4 pots. Highly unlikely anyway.

[left footed whooten]

I think I'm more partial to the 16" setup anyway.

EDIT: someone on nabisco busted out this piece of searchery, post 3. I was surprised:

http://forums.nasioc.com/forums/show....php?t=1140977

[doubleurx]

I've always used the Dunlop M3's. They have been great up here. I'll be running the same on the BMW this winter in the oh so unfortunate Run Flat model. I really hate that this car did not come with a spare tire.

[sperry]

Originally Posted by doubleurx

I've always used the Dunlop M3's. They have been great up here. I'll be running the same on the BMW this winter in the oh so unfortunate Run Flat model. I really hate that this car did not come with a spare tire.

I drove a co-worker's 335xi yesterday. All I can say about your lack of spare tire is "quit whining you ninny!" That car is awesome, who cares if it's spare-less!

[doubleurx]

Originally Posted by sperry

I drove a co-worker's 335xi yesterday. All I can say about your lack of spare tire is "quit whining you ninny!" That car is awesome, who cares if it's spare-less!

You're right. It just sucks that there are so few options right now and all the RFT's are a premium over the standard tires. Fortunately Dunlop does make the M3's in a Run flat.

[khail19]

Originally Posted by Dean

It used to be true with older design small blocked snow tires, but not true for the newer bread of siped snows.

I am looking for the research that I believe both Michelin and Pirelli did.

Dean, did you come across anything on the web that supports the "wider is better" snow tire theory? Personally, I think you are right but I'm wondering if there's any test results out there that show the numbers. I'm discussing snow tires with someone on a car audio forum and everyone else is saying that narrower is better.

[cody]

http://www.tirerack.com/winter/tech/...jsp?techid=126

Four Winter Tires...The Only Way To Go
Priorities for Sizing Winter Tires Are Different
Does your sports car, coupe, or sedan use wide, low profile tires that are mounted on large diameter wheels? Or does your light truck use large flotation-sized tires? If you're going to drive through lots of snow this year you'll want your winter tires and wheels in sizes that help put the laws of physics on your side.

A wide, low profile or large tire has to "plow" a wide path through snow which causes more resistance. The narrower the tire, the easier you can get through snow. We'll help verify sufficient load capacity and the appropriate diameter for your vehicle when you speak with one of our sales specialists or use Winter Shop by Vehicle.

Winter tire sizes should be based on one of the following:

The Optional Tire and Wheel Size from Your Vehicle's Base Model
This is often the easiest way to select an appropriate narrow tire for your car or truck. For example, a 2003 Lexus IS300 would store its original 215/45R17 tires in favor of optional 205/55R16 tires on 16" wheels.

A Minus Size Tire and Wheel
Minus Sizing is simply traditional Plus Sizing techniques used backwards. For example, a 2003 Volkswagen Jetta GLX VR6 would store its original 205/55R16 (or optional 225/45HR17) tires in favor of Minus One or Minus Two size 195/65R15 tires on 15" wheels.

In both of these examples, not only would snow traction be enhanced, but the cost of a Base Model or Minus Size winter tire & wheel package is usually lower than a package maintaining your vehicle's original size tires and wheels.

Winter Tire and Wheel Packages are available for many vehicles. Build one today or select our Preferred Package* for your vehicle.

[doubleurx]

I would agree with the Tirerack quote above for fresh snow. If you are driving in fresh snow, narrower will always be better. However, most of the time we drive on packed snow. This is when I believe a wider snow tire will give you better traction.

[Dean]

Originally Posted by khail19

Dean, did you come across anything on the web that supports the "wider is better" snow tire theory? Personally, I think you are right but I'm wondering if there's any test results out there that show the numbers. I'm discussing snow tires with someone on a car audio forum and everyone else is saying that narrower is better.

Other than the Michelin engineer I already quoted, not really.

Here is something siping specific. http://www.accidentreconstruction.co...03/103003b.asp

Again, I want to be specific. It is my understanding from the Pirelli engineer I have talked to that in our normal open highway conditions in CA and NV, not deep untamed back roads, that it is about the amount if siping that you can put on the surface of the snow/ice that is important, not the "digging" and higher PSI of surface area of a narrower tire.

I have been unable to find any scientific data to support or disprove this, only anecdotal and unsupported narrower is better statements and the siping comments from the Michelin engineer and article I provided.

It would be really nice if TR would take one of their BMWs and put 245, 225, 205 and 185s of the same modern siped winter tire and do some of their tests at the ice rink.

My guess is that there is a sweet spot at some PSI that creates the optimal clamping force as the sipes close as they come onto the surface.

[Kevin M]

I know it's anecdotal, but I would say that we could find conditions locally in the winter that would favor both wider and narrower tires without going to extremes. Basically if there is loose ice/snow/slush/whatever that can build up and prevent getting a lot of pressure on compacted ice or pavement, narrower is better. But on smooth ice or dense packed snow, I'd want wider.

[Dean]

Originally Posted by BAN SUVS

I know it's anecdotal, but I would say that we could find conditions locally in the winter that would favor both wider and narrower tires without going to extremes. Basically if there is loose ice/snow/slush/whatever that can build up and prevent getting a lot of pressure on compacted ice or pavement, narrower is better. But on smooth ice or dense packed snow, I'd want wider.

I agree. As with most things, "it depends" on the circumstances.

[cody]

I'll anecdotal you.

[sperry]

Originally Posted by BAN SUVS

I know it's anecdotal, but I would say that we could find conditions locally in the winter that would favor both wider and narrower tires without going to extremes. Basically if there is loose ice/snow/slush/whatever that can build up and prevent getting a lot of pressure on compacted ice or pavement, narrower is better. But on smooth ice or dense packed snow, I'd want wider.

+1

This is something that rally teams struggle with all the time in snow rally. Conditions vary so much, so easily, that the "ideal" tire for one mile can also be the worst possible tire for the next. Slush performance is very different from ice, which is very different from packed snow, which is very different from a light dusting over ice.

IMO, for winter tires, you should pick the tire that performs the best in the most dangerous condition, which to me is ice. A tire that's great on ice but passable in slush is far better than some slush racers that will get you crashed on ice. With the exception of the Tahoe folks, 90% of our winter driving here in Reno is on dry or damp streets... it's only in the morning after some fresh and before the plows that we really need "snow" tires. And then, the most dangerous roads we see in Reno are the roads after fresh snow is packed into ice by traffic (which is even worse when that's followed by more fresh snow).

So go for a tire that performs in those conditions. And for ice, I have to agree with Dean, basic physics seem to indicate the more sipped surface area you can get down on the ice, the better. Even if it's not "ideal" for cutting through the new snow to get to the ice or road underneath, it's still going to be the best traction for the really harry situations, and "not bad" in the rest.

Or, you could just get a set of these:

[Dean]

The problem with the TFG is that they have absolutely no feedback. There is absolutely no evidence that they work, you just have to go on faith that they will stick. Without that faith, you may well find yourself in the bottom of the deepest ditch.

[left footed whooten]

Yeah, they could really crucify you during the slightest bit of heretic driving....

I think its going to be Dunlop 3D's in 205 55 16 on steelies....$580 mounted and balanced. Hopefully I can get around shipping and pick them up in Sparks. Its a good deal, and I can save my OEM wheels for autox next year while picking up some pimpy wheels for every day.

[sperry]

Originally Posted by left footed whooten

Yeah, they could really crucify you during the slightest bit of heretic driving....

I think its going to be Dunlop 3D's in 205 55 16 on steelies....$580 mounted and balanced. Hopefully I can get around shipping and pick them up in Sparks. Its a good deal, and I can save my OEM wheels for autox next year while picking up some pimpy wheels for every day.

Those from TireRack? I believe they've moved out to Patrick by now... no more Sparks pickup. Gotta drive out 80 to their new warehouse.

[khail19]

Originally Posted by sperry

Those from TireRack? I believe they've moved out to Patrick by now... no more Sparks pickup. Gotta drive out 80 to their new warehouse.

Yep, some of my tire shop customers from Napa keep whining about having to drive "so much farther." I tell them it still beats paying and waiting for shipping from Indiana.

[left footed whooten]

Crap, I had no idea they'd moved. But yeah, so long as I spend less on gas than shipping....

[100_Percent_Juice]

I am going to go out there to get my wife some tires. I could possibly get another set for some gas money.

[van]

When do you plan on going Juice? I may contribute for a couple of rotors and some ATE if they have it.

[100_Percent_Juice]

probably within the next two weeks or so. I'm not really in a rush but I will be heading out there sometime. I guess I could go earlier if need be.

[van]

no rush for me either, just need em' a week or so before the oct autox.