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Discussion Starter #1 (Edited)
So the debates pretty much end up with endless 'everyone says' but never any actual tests of:
"Narrow tires are better in Winter than wider tires"

Now if you ask anyone, they pretty much say since the dawn of times that narrower Winter tires are better.
A few brave discussions have occured, and in them it is pretty clear NO ONE has actually taken the same car and two sets of tires and gone out and proven anything.
The general consensus is YES in deep snow narrow tires are better.
For the rest.. Ice, slush, straight line vs cornering.. Nothing. No tests.. all theory and endless discussions based on theory, with a few odd video clips tossed in which do not prove much.
The only test I ever was able to drag up is all in Swedish. With piles of graphs (in Swedish) about Nokkian tires 205 vs 225 along with pile of other brand tires. Unless you read Swedish not much help.

now some of the chats were pretty deep and interesting. But still no rel data. all theory why this or that.

My interest is in the wide tire. Seems IMO that a wider tire in many situations is going to be better. And then worse in some others..
Like I have zero need for deep snow traction. I have a lot of use for compacted snow/ice/slush traction. And turning. turning is good.

Anyway being my usual iconoclastic self.. Anyone run into some actual TESTS of wide vs narrow tires..?
The endless tests of snow vs all season etc do not answer any of the things I ask. Nor do the endlesss referrals to everyone agrees narrow is better.
Why? not one test.. none. zero.. if it was so easy to prove.. plenty of Utube bimbos would have vids up proving it? [drinking]
Even the TV show where those guys (Mythbusters) prove or disprove myths.. have declined to try to answer this. And Yes they have been asked.


Please feel free to add YOUR two cents to the debate and be sure to throw in all sorts of well known theory and ideas..

here is the most interesting thread I found: http://www.audiworld.com/forums/whe...-narrow-vs-wide-tires-winter-driving-2767164/
 

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A wider tire is GREAT for floatation. So naturally an offroading tire will desire to be wider. A wider asphalt tire can gain more traction due to an increase of rubber compound contacting the surface.

You already noted that a narrow tire will cut through deep snow, but that point is really mute on a fwd car. You have a 24" tire and 6" of ground clearance so at most 25% of the tire would be in snow before you high center (or start plowing). 95% of the time, a snow tire is in contact with less than a few inches of fluffy snow, nasty wet slush, glaring ice, cold pavement, or a combination of these. When fluffy snow is compacted, it provides a similar surface as ice. In this instance, it is the "biting" action of the tread (those lines cut perpendicular to the tread) and the compound of the rubber that are the two elements being exercised. The goal here, is to use a narrow tire to increase the pressure per area thus "digging" into the porous surface of the ice. By going with a wider tire, you may disperse the car's weight across too much contact area, thereby reducing the ability of the tire to bite into these small impurities of the ice. On to nasty wet slush. This is primarily controlled by the tread pattern (specifically the portion responsible for siping, or evacuating liquid). It is similar to hydroplaning a puddle. A narrow tire has a shorter distance from the center of the tread to the outside. So it will naturally be more effective at evacuating slush. Just like the principal of deep snow driving, a good tire will cut through the slush to bite into the surface below. Often overlooked in a snow tire, is the cold pavement performance. The rubber compound is most responsible for this. In this instance, a wider tire would be desirable (just as a summer tire grabbing warm pavement is). You'll find these oriented in "performance" or "sport" winter tires. They give up some of the nasty weather performance for better handling on cold-but-dry surfaces.

In short, for a Ford Focus that weighs <3000lbs a narrow tire will be better in almost every category of winter driving. My wife's fusion (3700lbs) runs a 215 winter tire which seems to perform well. My truck (8000lbs) uses a 285 winter tire. When I pick up winter tires for the new focus, I'm looking at 195 or 205.
 

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Discussion Starter #3
I have a theory that narrow tires good, wide tires bad, in snow, really got going when car started having more horsepower, and wider tires to go with it.
So you got the guy in his big motor Impala or Torino.. and it snowed.. Now being the sort who buys big horsepower he can't keep his foot off the heavy pedal. So the wheels spin like crazy and he goes noplace. But all those guys with dinky engines and skinny tires.. they have no problem going..
There is the start of the myth. [thankyou]

I really think that is a part of it. Old stories passed along down the generation from Father to Son, and all around so the guys in the know will repeat the old warhorse notions endlessly....
And naturally everyone buy it. We heard it, everyone says so, so it HAS to be true.
Then where is the scientific evidence? Where are the proofs so easy to show?
None.
Plenty about Winter tires etc. Nothing about tire width, except the same old stories that that is the way it is.
I want proof. Give me some site with facts showing two identical tires on two identical cars all the same except tire width and one sucks in all Winter conditions and one does not, and it is all due to the tire width.
No such tests.. Why? well we all already know.... LOL
I just want some answers..
 

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Mythbusters won't do an episode?

Ever think of where they're located & the budget for time/travel they'd need for a subject of little interest to the majority of their viewers?

Besides, it's uninteresting to "prove" the obvious.

I'll get back to this later in more detail.
 

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It's all about trade offs. There are no free lunches.

Narrow tires are great for getting through snow, slush and water. Wide tires offer more contact with the road surface, whether that be packed snow, ice, or pavement. You'll encounter both scenarios in typical winter driving.

Don't over think it.
 

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Discussion Starter #6
Besides, it's uninteresting to "prove" the obvious.
Like proving the Earth is flat. People got burned at the stake for not agreeing...
If you look at history, it is full of obvious 'fact' which are completely false.
Everyone was SURE they were right. After all, everyone 'knows' so obviously we all HAVE to be right..

(and yes, of course this is totally different... as everyone says when the obvious fact is well obvious...)

And i would not be so doubtful.. If there were only a few studies done. but there aren't any. At least none the Tire companies are showing (unless you can read Swedish?)... And no one else in the whole world thinks it is worth checking?
Now is when a billion dollars should fall into my lap. First thing would be the test.
Sets a pairs of identical cars. Budget small car pair, midsized family car pair. SUV pair, Sport car pair. maybe two pairs of sport cars.. One really sport, and one sport sedan.
Then the test areas. would need reproducable results.. Create ice, ice under snow, fluffy snow, thick wet snow, blizzard snow, skid pad with ice, snow slush, mix... several hills curves etc.. And then measurements.
I'd find out the TRUTH. Aliens really DO control our weather... NO.. Whether fat or skinny Winter tires are better and exactly WHEN each type is better.

I am not really worried too much. My choices are between a 245/40/18 (too big)or a 225/40/18.(too small)
Since no 235/40/18 is currently made in the tire I have decided on. And NO I will not say the brand. Least hoards of Aliens, or even worse... Smurfs, go buy them all up.
 

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Wide & narrow tires, so much confusion in how they work even before getting into snow/slush/ice considerations.

First off, since tires are affected a LOT by their basic construction as air filled balloons, the surface area in contact with a hard surface does NOT change with a change in width (all else equal).

I've got to emphasize this, as it's a common misconception that wider tires will give a larger "contact patch" than narrow ones. INFLATION PRESSURE is the one thing that will change the contact patch surface area, as the weight on the tire is supported by pressure x contact area.

W (lb.) = PSI x Area (sq. in.)

Now, we're not dealing with a perfect balloon here so pressure varies across the tire surface a bit. General principle holds closely, which is why a narrow tire will have a long narrow contact patch while a wide tire has a short wide contact patch.

So, if the contact patch is the same for different width tires, why should tire width matter? This is where the SHAPE of the contact patch comes into play, with advantages/disadvantages in different conditions.


First & most important for dry conditions & high speeds/cornering loads, the time the tread stays in contact with the surface affects it's heating from friction. As the tread heats up it's ability to grip is decreased, so a shorter contact time improves grip. Wide tire with it's short/wide contact patch minimizes the time the tread is in contact so grip is increased in dry conditions.


Wide sounds pretty good now, with better grip from less heating of each tire section as it contacts the ground. Why not use the widest tire practical?

Now for the rest of the story.....


For wet weather, water needs to be dispersed for tread to contact the road & wider tires have a hard time doing this. Tread patterns help, but there comes a point when dispersion isn't adequate & the tire looses contact with the road (aquaplaning). Narrower tires with their narrower contact patch have an easier time with this, less water needs to be moved so they'll maintain contact at higher speeds in the same water depth.

Getting into snow & particularly slush, this is one area where a narrow tire shines over a wide one. Slush makes water look easy to move by comparison, and you see depths randomly accumulating in the road that you'd seldom see with water accumulations. Odd puddles can be deep, but any you wouldn't be avoiding are short. Lines of deep slush in the road are unlimited in length, and are one of the worst hazards in Winter driving.

The next area where Winter traction varies from summer is the advantage you can get from LONGER contact with the surface. Tread heating & squirm isn't the issue it is when it's warm, rather longer contact to allow the sipes to squeegee water away & dig into the surface is the objective on snow/ice. Narrow tires with their longer contact patch are an advantage here.


Some of the Winter advantages to narrow tires are similar to tractors using tall narrow wheels instead of wide ones historically. The classic tractor tire was designed to cut through mud and get grip/support from compacted earth underneath the loose tilled soil/mud on the surface. Narrow tires in the snow can do the same thing, cutting through some of the snow while compacting & gripping on snow during the longer time they're in contact.


What works best for Snow/Slush/Ice is opposite to the best for warm/dry pavement. Fortunately cold roads aren't the problem hot ones are for tread heating, winter compounds/design can still help on a cold surface.

The Summer conditions similar to Winter ones for tire selection are wet weather & dirt roads. Off road situations are another subject, where grip/flotation from wide tires can be an advantage. Floating on top of Snow/Slush isn't good for traction/control, as you can see anytime someone tries to use large Mud tires in winter conditions.

Testing for aquaplaning is very difficult to do, one of the better visual examples was seen in old tire ads showing tread contact on glass as a tire drove over it through a water box.
 

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Why would a narrower tire have a longer contact patch? That would be diameter dependent, not width.
 

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Only when the tire doesn't deflect (the balloon example).

Width x length to get the surface area required answers that.

As width decreases, the length increases.

For an example, 3,000 lb. car has 750 lb. on each corner. For 35 psi. inflation, surface area required to support the weight is 21.43". 8" wide tire, contact patch length is 2.68". 5" wide tire, contact patch is 4.29" (all figures rounded to hundredths)

This is an approximation, as the flex of the tire does come into play to a small extent. Perfect flex & even pressure assumed for demonstration purposes.


For Elizabeth's question of sizing, small differences give small changes in results. Maximizing the difference would give the best results if you want to emphasize improved performance in specific conditions. (different wheel sizes/tire profiles required)

Cheers
 

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Discussion Starter #10 (Edited)
Why would a narrower tire have a longer contact patch? That would be diameter dependent, not width.
If you go look at the link I provided in my first post, (it is long but worthwhile, with many side roads travelled.) there is a discussion on the shape of contact patch. the primary problem with a 'long' contact patch is deformation. The tire deforms a lot more when it is making a long (vs wide) contact patch. the problems with that are heat, excessive bending wear.. And the tire gets to 'rest' a lot less in real time since more of it is always in use bending etc when there is a long contact patch. naturally this matters a lot more in racing and hot weather... but it is also inefficient.

And contact patch is more pressure dependent, but a narrower tire will have a longer one than a wide tire just because of being narrower.
 

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It's all about trade offs. There are no free lunches.

Narrow tires are great for getting through snow, slush and water. Wide tires offer more contact with the road surface, whether that be packed snow, ice, or pavement. You'll encounter both scenarios in typical winter driving.

Don't over think it.
This^^^^^^^ For your st, I'd run the stock size tire in either a a/s or a dedicated snow tire depending on how cruddy your winter is.
 

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I have some real world experience with narrow and wider snow tires. 185 and 205mm

my current tires that I use for ice rally x and some TSD navigation rally are only 185 wide. When I'm driving the back roads where I might be plowing through 8" of snow, I did want the narrow tire.

what I have found is that I corner too hard. I am putting too much side load on the tire that I am starting to eject studs. in retrospect I wish I had a 205 wide tires to have an easier time with side load.

in summary: deep snow and slush, narrow tire.
dry pavement, wide tire
fast cornering, wide tire
compact snow or ice, wide tire

however I am not advocating a tire wider than originally came on your vehicle.

my point is that consider how the majority if your time will be spent driving. I would assume that it would by dry, wet, or compact snow/ice. rarely deep snow and slush or standing water.
there fore go with a normal/wide tire size (not narrow). even if you do encounter deep snow and slush its not like a wide tire will be useless.
 

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Discussion Starter #13
I have some real world experience with narrow and wider snow tires. 185 and 205mm

my current tires that I use for ice rally x and some TSD navigation rally are only 185 wide. When I'm driving the back roads where I might be plowing through 8" of snow, I did want the narrow tire.

what I have found is that I corner too hard. I am putting too much side load on the tire that I am starting to eject studs. in retrospect I wish I had a 205 wide tires to have an easier time with side load.

in summary: deep snow and slush, narrow tire.
dry pavement, wide tire
fast cornering, wide tire
compact snow or ice, wide tire

however I am not advocating a tire wider than originally came on your vehicle.

my point is that consider how the majority if your time will be spent driving. I would assume that it would by dry, wet, or compact snow/ice. rarely deep snow and slush or standing water.
there fore go with a normal/wide tire size (not narrow). even if you do encounter deep snow and slush its not like a wide tire will be useless.
Thanks. Your response is jus what i was looking for. Great!
Thanks again.

(Yeah on the not wider than stock. Problem is the Snow tire I want is not available in 235/40 18 until two months AFTER I need to buy some.
The odd part is the 245/40/18 snow tire is still slightly smaller tread width (to the three tenth of an inch) as the OE 235/40/18 And it's max tire carcass width is also about the same on a 8" wide rim.
The 225/40/18 snow tire tread is a full inch narrower than the OE 235 tire
I am leaning to the 245 one.
 

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Yeah, a narrow tire will cut into the snow to permit contact with the road itself whereas a wider tire will be more likely to ride above the road surface. Of course, if you could have supper wide tires, wide enough that you could ride on top of the snow like a Snowcat, then that might be preferred, but there's no way to put tires that wide on your car even if it was legal.

There are trade offs, as mentioned, and since even the winteriest places tend to have snow cover only a few days of the year you're trading better traction for 5% of winter miles versus 95% of winter miles.

My tires now have 36K miles on them and they're not looking like they will last until/through winter with much tread on them so I'm probably going to be buying new tires in December. I plan to go with something like the IceX and put them on my stock 17" rims. Next spring I plan to order a new set of wheels and tires with TPMS so I can just swap out as the seasons change.


Brian
 

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245 is off the scale crazy wide for a snow tire!!! Holly smokes batman! I'm debating between 16x195's or 16x205's. I bought 16" Ford rims from a guy on here with almost new all-seasons which I plan to sell.

My prior car of similar weight (Contour SE/Sport with V6) came with 205x15's but I bought the base car's 14" 185's (Firestone) for winter (from tirerack for only around $35 each back then!). They were FANTASTIC, including on hard/ice (no idea why the other guy thinks wider would be better on harder snow/ice surfaces - if the ice is so hard that narrower tires won't bite/dig deeper, then you are on an ice rink and are screwed no matter what you have). They use a ton of salt here (Syracuse, which is often the snowiest city of over 100k population). So only when it snows faster than they can plow are the roads poor, so snow is the main issue here, not ice.

The stock 205 all-seasons (and BF Goodrich replacements) were horrible - too wide for the weight of the car (our 4000lb minivan has 205's!). The 3rd set (Uniroyal) on all-seasons were not too bad, so I didn't bother with snows while they were like new (1 or 2 winters at most).

The 185's were not good for braking on dry salty roads however, so I think 195x60x16's might be perfect. They are 0.2" to 0.5" shorter than stock, so the speedo will read 1% high and have less ground clearance. Easier to clean the spring/struts though with a smaller tire. Tirerack only has 4 brands/models in this size (195x60x16).

205x60x16's (not a recommended size) are tempting too (which is why I'm on here today - wondering if anyone is using them). Tirerack does not recommend 205x60x16. There are many snow tires in this size to choose from.
The 205x60x16 are 1/2" or so taller than the OEM 16" (215x55), but only 0.2" taller than my car's OEM 17", causing a 1 or 2% speedo error.
I wonder if anyone has gone this route - will they hit the fender liner? Around here, having extra ground clearance is a good thing.
The 185's were so good on the Contour, and the all-season 205's were so poor that I hesitate to go with 205's...plus tirerack does not list them as recommended
 

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There are trade offs, as mentioned, and since even the winteriest places tend to have snow cover only a few days of the year you're trading better traction for 5% of winter miles versus 95% of winter miles.
Only a few days of snow would be nice - we have a few days without snow! Well, not that bad, but 10' of snow is a fairly easy winter here.

The point of winter tires is that any tire is good enough on dry/predictable roads, but winter tires are much better when you need traction on unpredictable roads.

People forget that every mile on snow tires is a mile they are saving/extending their "summer" tires. So the cost of winter tires is not as bad as it seems.

The Bridgestone Blizzak (and I fear many others do the same thing) use very soft rubber which wears out quickly. Assuming one doesn't want to spend a fortune replacing high-end snow tires every 3 years, I think they are best for areas that don't get a lot of snow, but get packed snow/ice due to lack of salt trucks. I prefer traditional rubber that lasts longer. Firestone Winterforce is closest to what I had on the Contour for 10+ years. I replace two of the four with Winterforce for its final winter last year, and they were fine.
 

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Yeah, a narrow tire will cut into the snow to permit contact with the road itself whereas a wider tire will be more likely to ride above the road surface. Of course, if you could have supper wide tires, wide enough that you could ride on top of the snow like a Snowcat, then that might be preferred, but there's no way to put tires that wide on your car even if it was legal.
i've been thinking more on this.

does a tire ever really cut through the snow to the road surface? maybe for slush, but any other condition will just pack snow ice on top of the pavement.
this would argue that narrow tires dont have a benefit.

there is one outlier, rally cars. however, they do not use the same tires we do. Their snow tires would be really stiff sidewalls, also they are spinning their tires ALL THE TIME. the tread blocks would be shovelling snow out of the way, so they might actually be touching the pavement.


My prior car of similar weight (Contour SE/Sport with V6) came with 205x15's but I bought the base car's 14" 185's (Firestone) for winter (from tirerack for only around $35 each back then!). They were FANTASTIC, including on hard/ice (no idea why the other guy thinks wider would be better on harder snow/ice surfaces - if the ice is so hard that narrower tires won't bite/dig deeper, then you are on an ice rink and are screwed no matter what you have).
compact snow and ice are a uniform surface, just like pavement. wider is better in those situations, just look at every racing series, EVER. (except the rally tires like I mention above and 1930's grand prix racing, but they hadn't learned yet)

i don't doubt that your 185 firestones were great, but I'm arguing that in situations of high lateral load (and likely longitudinal), maybe narrow snow tires aren't as good as people think. And I will be voting with my wallet when i need new tires in a few years.
 

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Discussion Starter #19
i've been thinking more on this.

does a tire ever really cut through the snow to the road surface? maybe for slush, but any other condition will just pack snow ice on top of the pavement.
this would argue that narrow tires dont have a benefit.

there is one outlier, rally cars. however, they do not use the same tires we do. Their snow tires would be really stiff sidewalls, also they are spinning their tires ALL THE TIME. the tread blocks would be shovelling snow out of the way, so they might actually be touching the pavement.




compact snow and ice are a uniform surface, just like pavement. wider is better in those situations, just look at every racing series, EVER. (except the rally tires like I mention above and 1930's grand prix racing, but they hadn't learned yet)

i don't doubt that your 185 firestones were great, but I'm arguing that in situations of high lateral load (and likely longitudinal), maybe narrow snow tires aren't as good as people think. And I will be voting with my wallet when i need new tires in a few years.
This is my thinking as well.
Maybe cutting through a snowbank a narrow tire might be good. But the 'lateral' argument is the main one IMO.
Wide is good if you do not want to go sideways...

And I agree on the fact no tire is 'cutting down to the road' on snow. No way. not in any of my years of experience. the tire packs it down, period.
 

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We could have loads of fun with this discussion, there's a reason Eskimos have MANY words for snow to describe different types.

Snow conditions in general are very different than dealing with pavement alone, more similarities with some dirt conditions than pavement.

Rally cars ARE the best for comparison, they're the only race class running on real road surfaces. Except for the top tier World Rally cars, speeds are in a more "normal" range as well.

If you're getting appreciable side loading on the tires, you AREN'T on snow/ice and considerations might be different.

Narrow is the trick for Snow/Slush/Ice IMHO, and I'd be happy to discuss it in detail. Once pavement handling comes into the picture, you're back in a mixed use situation and what's optimum will change depending on the particular circumstances. Wider is then sometimes better, but even then not always. Wet conditions can favor narrow on pavement, and that is very common in the winter months.

I can't think of a "Racing Series" where wide is preferred for Snow/Ice/Rain, even the extreme Mud Boggers go for tall & narrow.

For all it's popularity, use of wide tires is only advantageous in particular circumstances. True IMHO like any other extreme.
 
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