Minimum tire tread depth for being effective in the snow?

[murphysf]

Hello

The question is when should I replace my tires on my 2000 RX300 AWD, with respect to the tires being effective in the snow.

The tires that are currently installed are All Season M&S tires Cooper CS5

I live in the SF bay area and this season I plan to make 7 trips this ski season, Already went 3 times and have another 4 trips planed between Jan and March.

 

[François Pugh]

ASAP, with some Nokian Hakkapeliitta Winter tires.
OK, you live in SF Bay, so maybe Hakkapelitta all-weather tires.

 

[Doug Briggs]

Quality tires are protection against accidents. Unlike actual insurance, they will actually reduce risk of injury to vehicle and body whereas real insurance only protects your wallet.

Only you can determine what the trade off is worth.

 

[François Pugh]

FWIW, Tire Rack recommends, "We recommend that winter / snow tires be replaced when they reach approximately 6/32" of remaining tread depth."
https://blog.tirerack.com/blog/colintirerackcom/tread-depth-and-winter-traction

 

[cantunamunch]

Keep in mind that squirmy alignment can lower the effectiveness of nominally still good tires. Driving over steel gratings is a good demonstration of this.

 

[James]

ASAP, with some Nokian Hakkapeliitta Winter tires.
OK, you live in SF Bay, so maybe Hakkapelitta all-weather tires.

Yeah it depends how much you care about handling. The Nokian WR G3 all weather tires I have def are spongier handling wise than all seasons. So if you care, I would go full snows winter, then whatever.
I have about 30k on them. They're still pretty good in the snow. I did an insane 9 1/2 hour snow trip in Nov. I kept expecting them to actually like plow. Interstate just a sea of white, prob 3-6 inches heavy snow, guess your lane. Even the last stretch in Vt was a good 6-8 inch of powder. I drove in the middle of the road.
The tires did pretty well. Lesser than they used to be, but still way better than all seasons. I had traction control off the whole time.
But full on snows would have been nice. Esp in the wet stuff.
They make an SUV version also.

Tire dealers can be... I don't know the words. The Nokian dealer I first went into to find out about snow tires, not all whatever, would barely acknowledge they had them. In fact, it seemed they didn't. It wasn't a small shop either. Truly odd. I said to the guy, "So, I can have any Nokian tire I want as long as it's the WR G3?" Yes, was basically the answer phrased like "Why would you want anything wlse? Makes no sense."

In the end I decided to go with that tire but found a dealer in VT that was 40% less, and would talk snows all day.

To answer your question- you should replace the all seasons immediately. You can justify, and find legions to agree with you, but it's ridiculous if you want snow performance. Like stopping. Or not sliding into a ditch. I've heard all the justifications. They really only work when it doesn't snow.

 

[murphysf]

Thanks.... Since posting I saw 5/32" and also 6/32" listed on tire rack.

Just curious if any of you monitor this or just replace them when the "look" worn or start to notice traction issues. I would expect if at 6/32" they are not effective that the driver should notice this.

 

[KevinF]

Thanks.... Since posting I saw 5/32" and also 6/32" listed on tire rack.

Just curious if any of you monitor this or just replace them when the "look" worn or start to notice traction issues. I would expect if at 6/32" they are not effective that the driver should notice this.

The snow tires on my car at the end of last season were right around 5/32 when I tossed them. (Honda Fit, I forget what the tires were). They did feel like they had lost a bit of traction on snowy or icy surfaces compared to when they were new.

They were still better than all seasons.

 

[headybrew]

I too went with Nokian Hakkepiilitas on my small truck and they are amazing. I bought them b/c of positive reviews and the size I bought had the X load rating vs. Standard on the other brand snow tires I was looking at.

 

[tball]

My experience is the winter performance of all season tires degrades well before they need to be replaced for summer use, while winter tires perform well in snow and ice through most of their tread life. You need to replace your all-season tires much sooner than you otherwise would if you use them in the winter. I'm pretty sure there are articles out there on the subject.

Michelin has some new all-season tires that are specifically designed to provide better performance throughout their tread life, but I haven't tried them yet.

 

[murphysf]

I did a bit of reading about the topic... It seems like the primary function of tread depth is to channel water / snow.

Isn't most of the winter snow driving conditions in Tahoe driving on packed snow? If so there isn't much channeling going on?

 

[Ken_R]

These:

 

[tromano]

I use the George Washington head quarter test for fair weather. Lincoln memorial penny test for snow tires

https://m.tirerack.com/tires/tiretech/techpage.jsp?techid=51

 

[pete]

Maybe an alternative view is what do you lose if replacing prior to 6/32nds? Presuming you start around 12/32nds, you use half the tires thread .. wait a bit and even if you wear down to 4/32nds, that represents another 2/32nds wear which is 1/16 added wear from the costs of buying a new set.

So, wait and save 1/16th of the cost .. and maybe risk some issues in performance?

You can then get into other scenario of selling em off before 6/32nds (say 8/32nds) losing 1/16 value but selling the tires off to those less worried.

Anyhow, I've gotten a more into trade off costs and rather increase performance by replacing early at low total lost value verses just looking at the overall cost, eg: cost of giving up 1/16 of the tread.

 

[François Pugh]

I used to use the coins, but now I use a $5 guage; it lets me know how much tread is left, and is easy to use and easy to read.

https://www.canadiantire.ca/en/pdp/victor-tire-tread-depth-gauge-0095501p.html

 

[scott43]

I just look at the tire and go..yup..new tires are needed..

 

[raytseng]

OK, as a fellow Bay Area person, 95% of your miles are on regular roads, you do not need dedicated snow tires.
You are better of with hybrid 4season tires or allseasons that tilt towards better snow performance.
The Michelin Premier LTX have the snow squiggles; even though it doesn't have 3peak.
The two 4season tires on tirerack that come up are

Goodyear assurance weatherready has 3peak
Bf goodrich advantage t/a

My brother also go the Vredestein quatrac 5 3peak (non-snow) 4season tires that were in the tirerack review; but didn't come up as a fit for your vehicle.

And/or the Continental Extreme Contact (also known colloquially as DWS or DWS06) has rubber that is more cold-temp friendly, and I've personally run a set of these.

I am also interested in the Pirelli Scorpion zero all season plus which is a new CUV/SUV tire. It has snow squiggles on it too, but very few reviews. (I enjoy some spirited driving in the other 3 seasons as well, and pirelli is no slouch for an euro-feel)

If you are anxious, your real insurance and money is better off buying a higher end set of chains (and/or traction snow socks); then also carrying shovel and sand/salt and escape mats. Then learn how to use all of that rather than just assuming your snow tires are going to save you. Then finally, you have to use your BRAIN to make that decision to pull over and say these conditions are rough; i'm throwing chains on even though I have AWD and new tires. No matter what people say, metal is going to outperform any rubber.

I don't know if you mentioned your current tire conditions. In your next trip, go find an empty street or parking lot with some ice and snow, and go practice some emergency manuevers to see how comfortable you are.

For money and budgetting, your decision is if you can make it through this season (and then drive over the summer) and delay your purchase for next fall; or do you need it now.
If you don't like your tires, pull the trigger and get on something you enjoy and feel safe in.

 

[raytseng]

As far as the tread depth recommendation thing, the real issue is the winter sipes usually don't go all the way down. So with a half-worn tire, most of the squiggles are gone. Unless you're going through the trouble to re-sipe your tires, the sipes going away are the real issue and reason for the tread depth recommendations (as well as the rubber typically getting harder after a few seasons).

The Continentals with DWS stamping helps automatically show that behavior, when the S can't be seen anymore, they are recommended only for dry/wet; then when the W is worn away, then Dry only, etc. I wish all tires would use similar indicators.
So taking this info, I think a basic evaluation is just look for the squiggles. (e.g., if you see all the squiggles you're fine; if your missing a lot of squiggles, it's time to re-think). This is especially useful when picking up a rental on ski trips.


The Michelin Premier does advertise they make their sipes with special feature that they get bigger as it wears down, so it should have similar performance throughout the lifespan. However not sure if that's only for Rain or with the winter sipes as well.