NYImola::NYMisano

Seen alot of talk about snows "feeling" like they lose there grip after a few years even with plenty of tread depth left (myself included) - anyone know the facts?

ex-quattro PETE

Never heard of that.

NYImola::NYMisano

Its been discussed here in the past from time 2 time

jprice@CPS

That statement is too large a generalization. There are many types of winter tires.

There are 3 main reasons this could be the case

1) Many winter tires have a different rubber compound on the outside half of the tread. When this wears down, you are left with a less agressive rubber compound more comparable to an all season tire. The Dunlop Graspics and Bridgestone Q rated Blizzaks are this way (and I'm sure many others too)

2) As the tire wears down, and the tread depth is reduced, there is less volume for the snow/slush to be evacuated into. This makes it so the tread has a harder time finding the road and giving you grip.

3) As the rubber ages, it can become harder. The tread blocks need to bend and flex to give you grip in the snow and particularly ice.

Another factor is the type of winter tire. A Q rated winter tire is going to wear out faster than an H rated (or higher) winter tire. The Q rated has softer rubber which wears quicker.

And finally, there is of course how many miles you put on it during the winter, and how the tire is driven (Agressive driving = shorter life)

One of the reasons I like to recommend Nokian tires is they last longer than most of the competitors, and provide a more even grip throughout their life.

Hope this helps.
-Jordan

jprice@CPS

Here's some quotes taken from tirerack's website:

<a href="http://www.tirerack.com/a.jsp?a=AR4&url=%2Ftires%2Ftires.jsp%3FtireMake%3D Dunlop%26tireModel%3DGraspic%2BDS-2">Dunlop Graspic DS-2</a>
"NOTE: The first 55% of the Graspic DS-2's tread depth features Dunlop's high-grip silica-enhanced compound while the remaining 45% features an all-season tread compound. Snow platform indicators (basically, snow wear bars) are molded into the Graspic DS-2's tread grooves to inform the driver when ice and snow traction will be reduced as the tire's tread wear reaches the point where the premium high grip silica tread compound is about to wear away."

<a href="http://www.tirerack.com/a.jsp?a=AR4&url=%2Ftires%2Ftires.jsp%3FtireMake%3D Bridgestone%26tireModel%3DBlizzak%2BWS-50">Bridgestone Blizzak WS50</a>
"NOTE: The first 55% of the Blizzak WS-50 tread depth features the Tube Multicell Compound while the remaining 45% features a standard winter tire compound."

<a href="http://www.tirerack.com/a.jsp?a=AR4&url=%2Ftires%2Ftires.jsp%3FtireMake%3D Goodyear%26tireModel%3DUltra%2BGrip%2BIce">Goodyea r Ultra Grip Ice</a>
"The Ultra Grip Ice uses multiple tread block sizes which are strategically aligned around the tire to minimize noise and enhance ride comfort. It features Goodyear's patented Ice Over Winter (IOW) tread compound which layers an ice traction tread compound (enhanced with silica and specialized polymers) layered above a more traditional winter tread compound. As the Ultra Grip Ice wears and the ice traction compound wears away, it reveals the winter tread compound for the remainder of the tire's life."

NYImola::NYMisano

Tirerack didnt have that info when I bought my snows 4 years ago, not sure the same technology was even used.

ex-quattro PETE

If you go by what NYImola stated, you should throw away a 3-year-old tire even if it's never been on a car.

The main issue is wear. If within 3 years you wear out 50% of your tread, then yeah, you could say that winter tires were only good for 3 years, but if takes you 5 years to wear 50%, then 5 years it is.

There isn't some magic time barrier that says that on its third birthday, a winter tire suddenly becomes useless, which is how I understood NYImola's original post.

NYImola::NYMisano

Dunlop WinterSport M2's - which started handling horribly at the end of last winter.
He does include comments that the compound needs to say soft - rubber does start to dry out even after just a few years.

ex-quattro PETE

and 4mm is about 1/2 of the original tread depth of most tires.

The less tread, the less bite a snow tire has.

I have a set of Michelin Pilot Alpins that have been through 3 winters, have at least 80% of tread remaining (I don't drive much during winters), and are still as good (or as bad) as when they were new, IMO.

jprice@CPS

I had interpreted the question differently ;-) (ignored the subject)