What tread depth to change at?

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Recently had tires rotated on both cars. 7/32's left on the Prius, and 10/32nds left on the Hyundai.

How are my tires doing? the Prius tires (Yoko Avid Ascends) have 33k on them, the Hyundai tires (Yokohama Geolandar HTS) have 16k on them.

What do tires start out at and when should they be changed?
 
10/32 is practically new. Most tires start at around 11/32 or 12/32.

For best wet traction, you want to replace them at 4/32, alas, the bare minimum (by law) is 2/32 which is at wear bars.

I've seen TireRack recommend having at least 6/32 of tread left for optimum snow traction.
 
+1 at the wear bars (that is why they put them there) is the legal limit you have to change the tires here but I normally change them before that since wet performance is going/gone well before that.

Cracking and uneven wear normally get tossed before getting to the wear bar in a few vehicles in the family.

Bill
 
Start looking at 4/32. When you find a good deal on the the tires you want pull the trigger.
 
Originally Posted By: Bill in Utah
+1 at the wear bars (that is why they put them there)


I follow this dependant on season. That tends to be the really huge factor. I run my all seasons into winter so at 4/32 I tend to be getting the itch to get a new pair before the snow and ice causes my destruction.

But in summer on dry pavement? I drive all the way down into the wear bars before I even consider changing them. I paid for the tread I plan to use it.

Plus performance on dry tarmac is fantastic with a nearly completely spent tire.
 
For wet surface 4/32 is about right, for snow and ice 5-6/32 is adequate. Because we have no rain in So Cal for 8-9 months from April till Dec, there are more than 10% of all vehicles with at least 1-2 tires below 2/32 during summer months.
 
Dry performance is unaffected all the way to 2/32.

Wet performance is terrible at 2/32. Tire rack found that doubled stopping distance. Even 4/32 was bad, stopping distance was right in between new and 2/32.

Tire rack can confirm the starting treading any tire.
 
If snow is involved 5/32" is the time to seriously consider buying new ones. Some do okay others are near dangerous in winter conditions.
 
Most new tires start out at 11/32 or 10/32 and minimum legal tread depth for tires is 2/32. That again is the legal minimum and doesn't mean it is safe IMHO. I think 4/32 is a good time to replace or seriously start thinking about replacing.

I start to notice loss in performance around 4/32. I replaced my last tires at 3/32 and they were pretty shot at that point in their wet performance.

Braking distance in wet conditions drastically increases with worn tires. I think tirerack has a video on this. Watching that video will scare you enough to not drive on tires with 2/32. The unfortunate fact is that with every mile on the tire and loss of tread the tire will perform worse until it reaches the end of its life.

Long-haul truck tires start out with about an inch of tread and they last ~200,000 miles between retreads.
grin.gif
 
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Originally Posted By: FoxS
Dry performance is unaffected all the way to 2/32 0/32.

Wet performance is terrible at 2/32. Tire rack found that doubled stopping distance. Even 4/32 was bad, stopping distance was right in between new and 2/32.

Tire rack can confirm the starting treading any tire.

Fixed for you.

I had the rear of my S2000 went down to bald (0/32 in the center, 0.5/32 on the sides) in summer months some years ago. Performance/handling on dry pavement was better than full tread.

If the road is slightly wet then the car is not drivable with less than 1/32.
 
The Nitto's on my pickup had 16/32" when new. My tire shop just gave me a depth gauge when I asked to buy one. Good luck.
 
Originally Posted By: HTSS_TR
Originally Posted By: FoxS
Dry performance is unaffected all the way to 2/32 0/32.

Wet performance is terrible at 2/32. Tire rack found that doubled stopping distance. Even 4/32 was bad, stopping distance was right in between new and 2/32.

Tire rack can confirm the starting treading any tire.

Fixed for you.

I had the rear of my S2000 went down to bald (0/32 in the center, 0.5/32 on the sides) in summer months some years ago. Performance/handling on dry pavement was better than full tread.

If the road is slightly wet then the car is not drivable with less than 1/32.


Thanks for fixing that but at 0/32 your dry performance will certainly be affected if you have a blow out! I'm presuming there is a safety reason, even in the dry, why 2/32 is the legal minimum.
 
Originally Posted By: GMFan
Most new tires start out at 11/32 or 10/32 and minimum legal tread depth for tires is 2/32. That again is the legal minimum and doesn't mean it is safe IMHO. I think 4/32 is a good time to replace or seriously start thinking about replacing.

I start to notice loss in performance around 4/32. I replaced my last tires at 3/32 and they were pretty shot at that point in their wet performance.

Braking distance in wet conditions drastically increases with worn tires. I think tirerack has a video on this. Watching that video will scare you enough to not drive on tires with 2/32. The unfortunate fact is that with every mile on the tire and loss of tread the tire will perform worse until it reaches the end of its life.


Most of mine by 4/32" are getting noticeable issues in water. If I could drive only on dry days maybe I could get away with less. I took my WRG2's to 3-4/32" and it got bad in rain, then we got an early snow and car was almost undriveable. Of course this happens when your away from home with out much choice.

My original MXV4 S8's at 4/32" of course going to work it started to rain then down poured for a short time on the Expressway. Road crown etc. is NO FUN when you drift/hydroplane from left lane to middle lane at 65mph. Luckily nobody was next to me when that happened. I also know better than to hit brakes or turn wheel at that point, many don't and panic. No panic, stressed yes, happy no issues yes, changed tires next morning without a doubt.

Here is that video.... Panic stopping 4/32"
 
The quarter test is the standard that should be followed, easy to execute, simply put a quarter in the tread and if you can see the top of Washington's head it is time to change the tires.

Needless to say the penny test does not cut it.

Tests show that it takes twice the stopping distance between the penny and quarter test.
Also think about water and snow factors.
 
In Western Wa. we get too much rain for me to run tires down below about 6/32"

Trying to squeeze tha last couple thousand miles out of a set of tires,when they're the only thing keeping you out of the ditch is foolish IMO.
 
Originally Posted By: FoxS
Originally Posted By: HTSS_TR
Originally Posted By: FoxS
Dry performance is unaffected all the way to 2/32 0/32.

Wet performance is terrible at 2/32. Tire rack found that doubled stopping distance. Even 4/32 was bad, stopping distance was right in between new and 2/32.

Tire rack can confirm the starting treading any tire.

Fixed for you.

I had the rear of my S2000 went down to bald (0/32 in the center, 0.5/32 on the sides) in summer months some years ago. Performance/handling on dry pavement was better than full tread.

If the road is slightly wet then the car is not drivable with less than 1/32.


Thanks for fixing that but at 0/32 your dry performance will certainly be affected if you have a blow out! I'm presuming there is a safety reason, even in the dry, why 2/32 is the legal minimum.


I'm 99% sure that is because of wet performance. With no tread I don't think the tire run hotter, if anything it should be cooler, less squirm and more road contact. Does anyone know when 2/32 became law? I'm guessing years and years ago, when limits were lower, or people just plain drove slower in the rain.

I've done the same, to the wear bars on summer tires, just drive slower in the rain. Winter needs full tread, or winter tires. However I've gotten rid of more than one set because I didn't rotate properly.
 
Originally Posted By: supton
........Does anyone know when 2/32 became law?......


The first time this was regulated was with the advent of tire regulations in the late 1960's. It isn't actually a "law", but the regulations required a wear indicator at 2/32nds - which was taken as a minimum. Some state laws differ - some states don't have any regulations at all.

But the 2/32nds has been around so long and is so well accepted that the courts act as though it were law.
 
Depends. For me - I wear them until they're corded. But I do track/autox, and on the cars at least - go thru tires more often then the average person. [censored], the tires on my wagon have been past that since I did the engine swap about 8k miles ago, and I light those things up EVERYWHERE and still haven't corded a rear yet. I've taken 615's and RS-2's out on Road Atlanta that started out past the wear bars before. I bought a set of 285/70/17 Terra Grapplers for my truck off CL that were at the wear bars. So far have about 7k miles on them and they haven't worn hardly at all.


But, if you're average joe driver, and don't want to worry about a possible loss of traction here or there - yes, start looing for deals at 4/32nds, and probably buy something by the time they're hitting the wear bars. I might be interested in your take-offs
smile.gif
 
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