Robert D

Now, I've been reading up on this topic from websites due to this thread gone wrong from the Boxster forums (link ). What are your thoughts about tire aging when in storage. I know many of you have extra sets of wheels and tires which spend long periods of time being stored. When is it too long for a tire to be stored and still safe for use? From what I've read, a tire should not be put into service after 6 years and should be replaced at 10 years...thoughts?

tifosiman

Wow, that was a post-gone-wrong.

75ohm

Disregarding tire wear, even perfect tires without wear should no longer be used if older than 6-8 years depending on "aging" condition. Check your DOT codes for week/year of manufacture.

Matt H

Robert, finally a subject I am an "expert" on.

The Rubber Manufacturer's and the Tire Industry have no official position. Mainly because no one can tell you a tire is "bad" after X period of time. The auto makers are not tire experts (actually, there are a number of people here who probably have more tire knowledge than Chrysler) and as such their recommendations are, to me, worthless. It would be like me telling you that your Ford needed to be sold at 6 years.

There are far too many variables to determine when a tire is no good due to age. Probably the most important is the storage, how hot, how wet, how long, etc.

JATMA (the Japaneses Auto manufacturers) have recommended 10 years as a guildine. That does not mean the tire has to be replaced or needs to be but it should be inspected and probably replaced. A tire checked weekly and rotated and balanced often on a car in excellent condition might last considerably longer than 10 years (though I wouldnt want to drive on it long). Bridgestone/Firestone is following the JATMA recommendation and I think you will soon see the other major manufacturers follow suit. Reasoning is probably liability.

In short: Not a chance in hell that every tire is bad after X date (this isnt beer).
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

Matt H

Zero scientific data to back that statement up.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

75ohm

You can garage a car on stands for years without driving it and dry rot your tires. If you have balanced, rotated, and driven normally on them for normal wear/tear, depending on the "elements" that you so eloquently stated and I previously summarized, they will be affected.

I wouldn't say zero, per chance, but rather, not concrete... for your review:

http://www-nrd.nhtsa.dot.gov/pdf/nrd...g_MacIsaac.pdf
http://www-nrd.nhtsa.dot.gov/vrtc/ca...experiment.pdf
http://www-nrd.nhtsa.dot.gov/vrtc/ca...inglessons.pdf (good info)

While I do agree that there is little scientific data that is currently available from "the Industry" I would hope that you would also agree that there is little reason to speculate that exposure over time will have an adverse affect on tires.

Matt, I appreciate and respect your opinion and position. I will further clarify my statement for you and others that as a generalization, while erring on the side of caution and in agreement with you, that inspection takes precedence, depending on the aging parameter that we've eluded to.

Personally, I would opine that the Industry is looking both at liability and replacement factors regarding any possible statement regarding aging.

Robert D

Matt- your thoughts are exactly what I believed prior to research (which confirmed my beliefs). The sources which I accessed include the National Highway Traffic Safety Administration (NHTSA) and the British Rubber Manufacturers Association (BRMA). The BRMA agrees with JATMA regarding the 6 to 10 year rule. The NHTSA did not dispute the 6-10 years as of yet. They are still researching a way to reliably test a tire...and there are several methods they define.

From what I've learned, there is no way to visually inspect a tire for condition due to aging, but there are ways to visually inspect a tire for condition due to use. With no conclusive scientific evidence supporting the 6-10 year rule set in place by JATMA, there is also no documented scientific evidence I found to void their claim. Until the NHTSA releases their findings, I'll go along with the 6-10 rule because there is no real way to inspect a tire for age, only use.

Robert D

Yes 75ohm, I read those PDF's as well. From what I gathered they are researching a reliable method to test tires condition from aging.

75ohm

Matt, what is your recommendation for inspection on such topic?

Robert - agreed...

I'm interested in the topic directly due to the condition of a set of tires that I have that are 8.5 years old by manufacture date and have ~15K miles on them, been rotated/balanced, not driven hard, properly inflated (even in storage), and are on a stored car in my garage... that have cracks on the tread.

To add another variable, Matt, what's the word on using nitrogen versus air for fills?

Chris_924s

Interesting subject. In my experience tires will dryrot due to dry and UV conditions, dont discount heat/ cold cycles.

I wont run tires over 5 years old- regardless of treadlife. seems like an accident waiting to happen.
Having stored a car on blocks over 5 years, (YES it was the corvair.. luckily the tires were cheap 13's ) the moment the tires were inflated they all slow leaked. They were less than 6 months old (I'll define this.. they were MOUNTED NEW within...) when the car went into climate controlled storage.

as long as we are on this train... does tire dressing (Pick your poison here) lengthen the life of the rubber? inhibit or extend sidewall flexibility - or no data??
Matt- I wait breathlessly for your guru input here.

Robert D

Chris, from what remember from an Excellence article a few years ago...cleaning and using protectant on tires (depending on the product) will aid with preventing damage from UV.

Robert D

Check this out Chris. I don't know how reliable the information is, but it does seem to make some sense to me.

http://www.howtocleananything.com/_n...autowheels.htm

Matt H

No disagreement, however, not you, nor SAE, nor RMA, TIA, JATMA, NHTSA, nor anyone else can tell you when that time is. I can store a tire outside in McAllen, Tx and it might not be good in 24 months, I could also store it in perfect conditions and it might be good for 20 years.

Liability 99%, replacement possibility 1%. There are estimated to be less and .5% of tires on vehicles older than 10 years, but that is only an estimate.

Kind of, I have a 223 page guide at my desk that would disagree but I am not an engineer. I have "insider" information but that is relative. Certainly one can inspect for dry cracking, ozone wear, etc that have nothing to do with use. One can also check for about 1K different use related items.

Dont hold your breath, they want no part of this aside from the grandstanding. Until someone can bring them evidence that says on the 1351st day this tire is no good I dont think they are going to do anything except maybe issue an avisory. That wont happen because it isnt possible.

75ohm, do you have any pictures of them? If the cracks are apparent to you visually it is probably time to dump them. I would bet the cracks are from heat cycling and not age.

Nitrogen is a fine inflation method, there will be less seepage through the innerliner, however, it does not negate the need to rotate your tires nor check the air pressure often.

Almost guarantee it was from the bead are, the valve stem or the valve core, all common problems on tires that sit a long time.

It depends on the dressing, some of them actually speed up the breakdown of the rubber itself. Your best bet would be to ask the product manufacturer for data (which they probably wont have). I will see if anyone in the engineering dept. might have more insight.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

Scootin159

Matt, not to get too far off topic, but could you possibly settle an urban legend I've been hearing lately. It basically says that with radial tires, you should never drive on them the 'opposite' way, or else they'll fall apart. Basically the beleif is that if you spin a tire one way, the belts get used to it, and if you drive it the other way, the tire will fail.

I have a hard time beliving this however as it seems several cars have rotation patters that suggest this very practice (with the exception of directional tires obviously).

Matt H

Assuming non-directional tires you should always follow the manufacturers recommendation, generally that is for cross rotation. Front tires to the back and cross the rears to the front on RWD (But I havent done a rotation in forever, let me double check I dont have that backwards in the morning).

Whatever the case may be I assure you they will not fall apart. Frankly, there are even some directional tires that are cosmetic only and will work the same mounted either direction.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote