Minimization

Tire Rack customer service rep. just told me 3 seasons (only 15-18 months total use)! They claim it is because they have softer rubber- I thought they were harder rubber??

Anyway, I have 4 seasons (20 months) on mine and the tread is way deep still and they still perform well in the snow. The only issue has been the annoying sidwall bubble situation, which I think has nothing to do with tire age.

RKA

Generally, 12-20K miles, depending on the particular model of tire. Some are very soft (like a Bridgestone WS50) and optimized for ice and snow driving. Those tires will tend to wear faster than something like an Bridgeston LM 25, which offers a firmer compound optimized for better dry road handling.

Generally when you reach 1/2 the original tread depth, the tire will no longer be optimal for winter driving. This can be for a few reasons. with the softer tires, they outer half of the compound is specially formulated to help you grip in icy conditions. With any winter tire, the shallower the tread depth the less effective the tire will be in the snow, and finally, the effects of age/use harden the tire, and you'll notice traction decrease slightly as the tire is used. By the time the tire reaches 1/2 it's original tread depth, it's a good time to get new ones if you want the best traction available for the car.

KOpork

is NE PA weather.

NYImola::NYMisano

The compund on some tires can go bad after 4/5 seasons w/ plenty of tread left. My Dunlop Winter M2's have 5/8 tread left and were like slicks last season - Gary on the tire forum posted about this a few days ago, and confirmed what was only my suspicion. Ordering some Nokian's for this winter.

S4AVT

mostly 2 season... and sell it for 30 bucks

S4AVT

they still perform well in the snow... even you use more than 2 season but not on ice

OCA::DIY Motorsports

They still have tons of tread left. I do mostly freeway and streets and I don't baby them at all. I'm still shocked. I just can't kill these damn things. They are very stable at speed(up to 120 or so), but really suck at the cornering thing. Braking is sub par too.

Die you mother F'ers :-)

Rory

As a tire wears, the molecular structure of the rubber compound changes and tends to lose elasticity. This is more critical for snow tires than summer ones, since for them to be effective in cold and/or icy conditions they must be flexible enough to conform to the road surface and for the sipes to open up and bite. I'd imagine that for pure snow driving, tread depth is more important than compound.

I have Pilot Alpins on an S4 and like you there's plenty of tread left, but nonetheless it's time to change them.

Rory