What tread depth to change at?

[Bamaro]

Originally Posted By: HanDez
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.

TWICE, I find that hard to believe.

 

[Quattro Pete]

Originally Posted By: Bamaro
Originally Posted By: HanDez
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.

TWICE, I find that hard to believe.

Yeah, judging by the TireRack test posted earlier, it may be twice between brand new tires and 2/32, but not between 2/32 (penny) and 4/32 (quarter).

Still, a significant difference though.

 

[gfh77665]

Originally Posted By: FoxS

Thanks for fixing that but at 0/32 your dry performance will certainly be affected if you have a blow out!


Any tire with ANY tread depth, even a brand new one, will have dry performance be affected if you have a blow out.

 

[Rand]

Originally Posted By: gfh77665


Any tire with ANY tread depth, even a brand new one, will have dry performance be affected if you have a blow out.


pretty sure you missed the point of his comment.

 

[gfh77665]

Pretty sure I didn't. I have had brand new tires, less than 500 miles on them, have massive blowouts. Long story short, I bought a new Caprice Classic back in '95, and during its first real trip, during the first week I owned it, a blown OEM General tire at 75 mph almost totaled it.

Unless someone drives stupidly past the tread, into the cords and belts, etc,. blowout risk is all about the same.

 

[Rand]

I'd have to disagree. If you have 2/32" tread its much more likely to get a puncture or be damaged than full tread.

but obviously it can happen at any tread level.

I had some load range E tires that started out with 17/32's

I picked up 3 nails and never had an actual puncture.

 

[gfh77665]

Punctures generally result in flats. Mfg. flaws, not worn treads, generally are the root cause of blowouts.

BTW, I formerly worked in the industry. I speak from experience.

 

[Rand]

you are also very specific in your terminology. most people aren't

ex. people that say

"you just need to upload it to your computer from the DVD"


that's not correct but you know what they mean and just let it pass. etc.

 

[gfh77665]

The whole point of this forum is automotive discussion. If there is erroneous information out there, I don't have a problem challenging it with factual information.

 

[CapriRacer]

Originally Posted By: gfh77665
.........I have had brand new tires, less than 500 miles on them, have massive blowouts........


Originally Posted By: gfh77665
Punctures generally result in flats. Mfg. flaws, not worn treads, generally are the root cause of blowouts.

BTW, I formerly worked in the industry. I speak from experience.


Ordinarily I'd let isolated comments like these slide on by, but not only is this assertion untrue, it is being made such that it appears to be coming from a credible source. So get your popcorn out, this might be entertaining.

I entirely dispute that the root cause of "blowouts" is manufacturing flaws. First allow me to subdivide "blowouts" into 2 categories: 1) Rapid loss of inflation pressure, and 2) loss of structural integrity without loss of inflation pressure - recognizing that you could have both, but one would be the first thing that happened and lead to the other - and for the pruposes of this discussion, I am talking about the first thing.

#1 is by far the most common and is almost exclusively road hazard related. Many punctures do indeed result only in flat tires, but some of those will result in a) a run flat condition that is commonly confused with a "blowout", and b) a situation where escaping air further damages the structure of the tire (the more classic use of the term "blowout" - an explosion.)

#2 is pretty rare, but has gotten many people's attention due to the Ford/Firestone situation some time back. I have looked at literally thousands of tires that fit this description (I have been doing this for quite a long while) and I can count on one hand the number of tires that had manufacturing flaws. In my view, these are all design issues - that is, the key to fixing them is not changes in the quality (consistency or manufacturing processes), but changes in the specifications (design).

And let me state categorically that any tire that blows out with less than 500 miles on it is very very likely caused by road hazards, not manufacturing flaws.

 

[Hokiefyd]

Originally Posted By: CapriRacer
#1 is by far the most common and is almost exclusively road hazard related. Many punctures do indeed result only in flat tires, but some of those will result in a) a run flat condition that is commonly confused with a "blowout", and b) a situation where escaping air further damages the structure of the tire (the more classic use of the term "blowout" - an explosion.)


I imagine "b" is quite common. You can see this in things as small as a soda pop can and as large as a passenger airliner (at altitude). You have a chamber of air that is reasonably "sealed", and at a much higher pressure than ambient. Even a small breach in that chamber can cause a rapid and violent depressurization.

Shake a (full) pop can until your arm is tired, and stick it with a pin. You will end up with more than a small pinhole.

I imagine that a wheel/tire assembly would behave quite the same.

 

[gfh77665]

Originally Posted By: CapriRacer

And let me state categorically that any tire that blows out with less than 500 miles on it is very very likely caused by road hazards, not manufacturing flaws.


Baloney. My tire blew out on a velvet smooth road just north of where I live. My wife was sitting beside me when it happened. She and I would definitely have known if I hit something. And I hit NOTHING.

Further more, another of the cheap OEM Generals blew out on I-10 about 5000 miles later. Fed up, I went and got a new set on my still new car.

The Generals were garbage. Two blowouts, manufacturing defects. NO doubt at all.

Additionally. I have had many FLATS in my time, but never, ever did one blow out.

That, categorically, is the factual truth of the matter. Nothing you or anyone else can say can change that.

 

[KitaCam]

I'd just like to add a minor rant out to retailers that push the safety barrier by not honoring mileage warranties until the tire gets down to 2/32 or the treadwear/worn/gone bar...

 

[eljefino]

Originally Posted By: KitaCam
I'd just like to add a minor rant out to retailers that push the safety barrier by not honoring mileage warranties until the tire gets down to 2/32 or the treadwear/worn/gone bar...


They just want to see if one side will remain at 3/32 so they can claim your lousy alignment was the cause of the rapid wear...

 

[Dominic]

Originally Posted By: RamFan
Start looking at 4/32. When you find a good deal on the the tires you want pull the trigger.


+1 I do this as well. I also measure all the way across the tread to make sure I don't have a overly worn spot. Typically 4/32" is around 30-40K miles on the best high performance all seasons.

 

[GenSan]

If you are making a claim on warranty tread life then you have no choice but to *cautiously*(think hydroplaning) wear tires down to wear bars(2/32" 's) but if not then have them all replaced around 4/32" 's unless you plan to only drive when the conditions are dry.