Opinions on tire tread depth... Snows vs. A/S

[TwinTurboGTR]

So I wanted to get an opinion on tread depth from some of you guys. Did a search and there is a ton of stuff on A/S vs. Snows... but few on tread depth and difference.

SO here we go...

Right now on the 4.8is, I have Scorpion I&S mounted on 18's... Now the Pirellis are 9 seasons old and have 5/32'nds on them. I think new they were 14/32nds. Now I know they are worn and are pretty much to the end of their life, but, the sipes and such are still there. Now, these tires were used on the 4.4 for the majority of their life and they were awesome. Last year thought my pop complained that the tires weren't as good as when they were new. Of course. So I swapped snow shoes with him. I gave him my Blizzaks and I took his Pirellis.

Last year I ran the Blizzaks and they had 12/32nds on them... they were ok.. but not really great. I had slipping and sliding and DSC was working overtime in many cases. But this season, because I knew the Pirellis were shot, thinking tread depth was important, I gave him my snows and took his over to squeeze one more season out of them.

With all of the snow this year, I asked my pop how the X was with the new snows, and he said the same thing... Feels like they are worn. He was slipping and sliding a bit and such. Checked the depth and they are at 10/32nds. So still plenty of tread there.

So now I am left scratching my head. Technically the Blizzaks should be doing great... but in my experience and my pop's, they kinda suck. We both agree, the I&S were much better.
I am tempted to put the "Summer" 20's on wrapped in the Conti DWS with 10/32nds all around and see how they do. But then again, I'm lazy and dont feel like swapping right now.

Anyways, I guess my question is... Do you guys feel a worn dedicated snow tire is still better than a All Season tire with a good amount of tread?

I've read that snow tires are really only good to half their tread depth because the compound begins to change half way through for stability. In my case, I would be well over that threshold of "Soft" rubber compound" Then again, I was always taught at tire with approx 40% tread depth remaining was still usable and stable... after that, the tires are considered boogered and should be changed...

Just curious I guess... Ok, let the answers fly!

[upallnight]

Stopping driving with a LEAD foot as though it was still summer. I see people in all type of cars driving on snow cover roads this winter and most of the time they are spinning their tires.

[TwinTurboGTR]

Originally Posted by upallnight

Stopping driving with a LEAD foot as though it was still summer. I see people in all type of cars driving on snow cover roads this winter and most of the time they are spinning their tires.

This really doesn't give me a proper answer. But, I hardly think driving 25 MPH in a straight line on a snow covered road and feeling the back end slide out as driving with a LEAD foot.

You are always going to see some sort of tire spin in snow, its not a rarity. I'm sure some drive like morons like following to close or brake checking and such, hense why you see them in the ditch or rear ended.

[BIMMER_BLUEBLOOD]

my opinion, a good set of winter tires are worth the investment. i just got an X5 in november, threw on Michelin Alpins and have been coasting thru all these NYC snow storms like its a summer day. great traction, turns well, brakes very well... A/S tires on the x5? not the greatest when it comes to traction.

[JCL]

I replaced my Scorpions when they had 7 or 8 32nds left. They have lost their original benefits at that point. I wouldn't expect your Scorpions to perform well at all. They are effectively worn out. As well, they are nine seasons old and technology has progressed in the interim. Finally, they will be noisy.

40% remaining is fine for a summer tire but with a dedicated winter tire they will be compromised.

I like Blizzaks, but different tires will work differently in different temperature ranges, on deep snow vs icy conditions, and will retain their performance differently as they wear. Your testing has told you you need two new sets of winter tires for the two vehicles, at least to replace the Scorpions and perhaps to replace the Blizzaks.

[TwinTurboGTR]

Originally Posted by JCL

I replaced my Scorpions when they had 7 or 8 32nds left. They have lost their original benefits at that point. I wouldn't expect your Scorpions to perform well at all. They are effectively worn out. As well, they are nine seasons old and technology has progressed in the interim. Finally, they will be noisy.

40% remaining is fine for a summer tire but with a dedicated winter tire they will be compromised.

I like Blizzaks, but different tires will work differently in different temperature ranges, on deep snow vs icy conditions, and will retain their performance differently as they wear. Your testing has told you you need two new sets of winter tires for the two vehicles, at least to replace the Scorpions and perhaps to replace the Blizzaks.

Crappppp... lol... I know the Scorpions need to be changed, but you think the Blizzaks too? I think new they start out at 13/32nds... when I checked them last year they were at 12... date code stamped is 0412, which is the 4th week of the year in 2012, right? I'm pretty sure the first 2 numbers are the week of manufacture.

Anyways, do you think running the worn snow tires is still more beneficial than running fairly new All Season tires? Or is it a total wash?

Kinda tempted to throw the 20" wheels wrapped in the DWS and see how it does in the next snow storm... Who knows... Maybe I should just shush and just order new rubbers for the winter and call it a day.

By the way JCL... you're probably going to call me crazy but.... I actually think the fixed transfer case does a better job in sticky situations than X-Drive... Does that mean I should have stones thrown at me? haha.

[JCL]

I think your nearly new Blizzaks will be better than all seasons in winter conditions. I think your Pirellis are worn out and should be replaced. I can't compare your worn Pirellis to your all seasons because the answer is "none of the above"

My suggestion to consider replacing the Blizzaks wasn't because of tread depth but because you noted they didn't perform as well as you would like.

[upallnight]

Originally Posted by TwinTurboGTR

This really doesn't give me a proper answer. But, I hardly think driving 25 MPH in a straight line on a snow covered road and feeling the back end slide out as driving with a LEAD foot.

You are always going to see some sort of tire spin in snow, its not a rarity. I'm sure some drive like morons like following to close or brake checking and such, hense why you see them in the ditch or rear ended.

That would be driving to fast for conditions when the police officer fill out the accident report that you went into the ditch on a straight snow covered road.

[THE VEIN]

compound has a lot to do with it also. If the roads are icy I'd stay with the winter tires.

[racingbmwm3]

Pirelli's tire description is not sufficient to answer, but yes, some of the winter tires do change tread compounds around halfway to more of an all season type compound. Blizzaks originally pioneered that marketing the winter tire as a true all season, where it was expected that the 'winter' compound would last you through winter, then during spring the remaining 'winter' would get worn away and you could continue to leave the same tires on over summer into fall, then replace the tires the following winter with new ones.

I suspect the Scorpions are winter all the way through though. BUT, 9 years is pushing it for tire age. It's recommended tires get replaced anywhere from 6-10 years old, depending on manufacturer. Proper storage would affect the aging (dryrot) of the tires as well. Kept off the ground, constant cooler temp, out of sunlight?

I'd probably keep the Pirelli's on for the rest of this winter, then recycle them come spring. Pick up a new set of winter tires next fall. Check the latest tirerack comparisons when you do. I'm thinking my next set will be X-Ice or General Arctics, since my Scorpions are at the end of their treadwear.