Tire Reviews: Wide vs Narrow Winter Tires Tested
- Thread starter CapriRacer
- Start date
VERY interesting, as running Falken Eurowinter tires on my BMW 328i rear wheel 6 speed manual drive. Different sizes front and rear. I elected to run thinner and slightly taller than stock OEM due to availability for the OEM rims. Have had good results over the last three to four years, but they do decline significantly in performance as they wear (previous experience on a Porsche), even though the tread appears adequate.
Things I like about them...1. Comfortable ride in pothole Michigan. Softer - but some loss in cornering performance. 2. Price. Seem to be the best value at the time of purchase, recognizing they are NOT the best performing winter tires. Fine for me given the typical winter.
One thing I do notice is they have phenomenal grip in the wet!
Things I like about them...1. Comfortable ride in pothole Michigan. Softer - but some loss in cornering performance. 2. Price. Seem to be the best value at the time of purchase, recognizing they are NOT the best performing winter tires. Fine for me given the typical winter.
One thing I do notice is they have phenomenal grip in the wet!
That is roughly the same with snow ;-) with a twist.
If there is ice covered with snow it is better to be on the snow than dig to the ice - unless one has ice tires (studs, the bigger the better).
Krzyś
I think there is a bit of a "rudder" effect with narrower tires as well. So even if the tire isn't cutting all the way down through slush, it is cutting deeper and the longer contact patch has more squared off shoulder treads to cut into the slush and with some slip angle cuts even deeper.
I would never buy snow tires without squared off shoulder treads for this reason, as this cutting into the slush and snow effect at least scrubs speed better if a car goes sideways.
In the absence of empirical testing, I'm not convinced of the theory that a slightly narrower tire (such as going from 235/XXRXX OEM to 205/XXRXX, for instance) results in appreciably deeper "cutting". Conceptually, the loose material has to travel a greater lateral distance before being ejected from the tread voids (as opposed to rearward spray) and is of a greater total volume in the case of a wider tire, but what real-world effect does a ~10-15% difference make?
I think emphasis is on wrong performance variable. Narrow tire advantage is in slush, that snow between lanes, water (hydroplaning). I am not sure other performance variables are worth considering. It is give and take.
Why does the narrow tire provide an advantage in those conditions, and to what degree?
If you were racing, 10% more grip at times would be quite an advantage! I think the small advantages of narrower higher profile snow tires add up to a very noticeable difference in deeper snow and slush situations in terms of ease of driving and confidence.
Going way back in time, a bunch of us were at a buddies cottage in the winter, and my car was last in the driveway, so a friend borrowed my 92 sentra to for a bacon and beer run. I had that car on 155/80R13 snows and he couldn't believe how much better they worked than the 195 or 205 width snow tires he had on his Jetta at the time. This was about 6" of snow run over dozens of times, so not hardpacked but loose and rutted, and the narrow tires tracked straight through most of it with way less wheelspin and sliding compared to the much wider tires on his car.
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I wonder if this changes for studded tires that roughen icy surfaces. Is there a benefit to a longer, narrower contact patch where more of the tire is contacting surface that has already been abraded by studs?
There is less resistance. Narrow tire goes easier through slush and keeps vehicle more stable. There are numerous tests where narrow tires, summer, all season, winter, achieve higher speeds before hydroplane.
Agreed.
Again, basic physics.
A narrower tire has to move/displace less material along the vehicle path. A 10% increase in width is a 10% increase in the amount of snow/rain/slush that must be displaced to get the tire down to the pavement.
Very little traction from loose snow or slush. Zero traction from liquid water, which is why hydroplaning should be avoided.
You want the tire to get down as far as it can in most winter conditions, so that it maximizes traction. Narrower tires make that easier because the tire has to displace less material.
That said, the design and tread compound make a big difference. So, all of those things being equal, narrower should yield better grip because it gets down to pavement more easily.
That is why the original post is so interesting.
An example of this is shown in the video
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I don't disagree with anything you said. However, it doesn't address my complete question. To restate:
Why can't a wider tire be just as effective at evacuating a given volume of water per mm of tread width vs. a slightly narrower tire? Are we assuming a wider tire gains all of its width from solid tread blocks, or should the void spaces grow in capacity as the tire width is increased? Are we not simply asking a larger pump to move a larger volume? If not, why?
What is the measurable effect of displacing 10% more snow/rain/slush? Is it a 10% reduction in the speed at which hydroplaning occurs if all other factors are equal?
I'm not claiming the "narrower is better in the snow" theory is wrong - I'm just interested to see someone support it with something other than "basic physics" or "There are numerous tests".
Why is the amount of slush greater?
Because the area is greater.
A car traveling 100 meters leaves a track 100 meters long. The track width is (more or less, section width isn‘t the same as tread width) the width of the tires.
So - the 205mm tire leaves a track that’s 100m x 205mm. 20.5 m squared.
The 235mm tire leaves a track that is 100m x 235mm 23.5 m squared.
That’s a lot more slush to be displaced by the same weight, and if the car is at the same speed, in the same amount of time.
If the tires, by virtue of tread design and density of material, can move “x” in a given time, the narrower tires can do it at a higher speed.
Further, the longer, narrower contact patch is moving material over a longer distance, a longer dwell time, given its shape. So, more chance to move the slush/rain/whatever to the sides and let the tire tread get to the pavement.
The tread depth is pretty much equal on passenger car winter tires, and in general I would guess the "land to sea" ratio stays about the same as well, otherwise the wider tire would get noisy. What gets harder to do with a wider tire is get rid of the slush/water in the middle of the contact patch, and the wider the tire gets, the slower you have to go to evacuate all the water/slush in between the tread or "land" or it gets flooded and there will be water/slush between the tread and the road and you have none/little grip.
I'd guess the amount of force to keep a tire on the road at say 50mph in 1/2" of water increases exponentially as tire width increase linearly.
Also colder water is slightly more dense and has a higher viscosity.
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Not part of my question. It's a given that the amount is greater - the question is why can't it be displaced as effectively. ml/mm where mm is tread width and ml is displaced volume.
Just because I don't quite follow this doesn't mean I think you're wrong. I wonder whether it's a question of downward force (weight) or longitudinal energy, or some relationship between the two. Interesting.
I also like this. Something like how a longer barrel gives propellant more time to act on a projectile.
This is what I was entertaining as a possibility - I just haven't seen the data to support it. It makes sense that pumping matter through some system gets harder over distance. What I don't know is what that means in terms of measurable performance differences. At the extremes, the effect is intuitively obvious. Not so much when we're talking about +/- 30mm of tread width.
