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"new" tire age

I bought a new set of tires and noticed one of them had a mfg date that was almost 2 years ago. That doesn’t sound “new”, especially since tire rubber has a 5-7 year life expectancy. Tire dealer claims they can’t specify a maximum tire age less than 2-year old when ordering tires. Is that reasonable? I don’t recall ever getting new tires more than a few months old in the past.

Their deliveries of “new” tires may have been slowed down due to Covid. Or perhaps the tire factories have slowed down production.

I wouldn’t worry about it myself.

Don’t worry. Not an issue.

Michelin actually says you can get up to 10 years from the date of manufacture but really, unless you don’t do much driving you’ll wear out your tires before they “die of old age.” About a year ago I replaced a set of Firestones that had been on my car for four years and about 30k.

It is a commonly held belief within the tire industry that tires as old as 6 years can be sold as new. I say “belief” because I know of no study that confirms this.

HOWEVER, the company I worked for tested 3 year old tires and could not find any difference to freshly made ones.

Further, the USTMA (US Tire Manufacturers Association) has stated that they know of no data that suggests there is a defined age limit, but they recommend replacing tires when they are 10 years old.

HOWEVER, heat is the tire killer, and it is clear that tires in - say - Phoenix, age much more rapidly than tires in - say - Minneapolis. Many people in the hot climates suggest there is a 6 year limitation.

HOWEVER, the clock starts ticking when the tire is put in service (according to the tire warranties), so - referencing above - time in storage is not much of a factor when it comes to tire aging. The only reason the manufacture date is used is because you can determine that from the tire, but you would have to have the invoice to tell when the tire was mounted to the vehicle. - and people usually don’t keep that, nor do they remember when that happened.

2 Likes

Ozone attacks rubber.

Exactly, even when the tires are kept in storage.
So why accept “new” tires with a significantly reduced lifespan?

Only certain locations have enough ozone to affect tires in storage, and I bet most tires are more carefully stored these days.

Aging in the warehouse is not a concern, it is insignificant.

I have seen specialty tires up to 4 years old come from the warehouse. The only problem I have is that by some repair standards a tire over 5 years old can not be patched, it must be replaced if punctured.

One item I forgot to mention:

Tires have waxes, antioxidants, and antiozodants (AO’s) in the rubber to protect them when in storage - another reason why storage doesn’t contribute much to the tire aging picture. These flake off shortly after the tire is put into service.

I would not consider that a valid test.

A more meaningful test would be to

a) Determine the average age consumer keep tires.
b) Test a tire that is that age and a tire that is 3 years older.

Repeat test but instead of using average age, use a max average age.

Perhaps I could have worded that better: They wanted to know if their standard of storing tires in their warehouses for up to 3 years (before scrapping them as too old) had any negative affects on tire endurance, so they ran an industry standard endurance test and could not find any difference in the results.

This was particularly applicable to winter and unusual tires (unusual by size or type - low demand). But the testing strongly implied that tire aging really didn’t start until the tire was put into service. Tire aging in service was something they already knew about.

That sounds like they are only testing a 3yo tire to a new tire. Again I don’t think that’s a valid test. A more valid test would be to test a tire that’s been in service for 6 years compared to a tire that was in storage for 3 years and then put in service for 6 years.

Sounds like a reasonable test to me. Tire companies can tell if a tire’s condition is degraded without waiting 9 years. Are you saying there’s some concealed mechanism going on? The condition of the tire’s components can be observed and measured.

+1

It seems like the tire company was simply testing one variable: whether a three year storage period would change the failure rate of their usual tire tests. It was still the same life test they always performed, just on 3 year old tires.

There might be. Many materials don’t degrade lineally. At 3 years they may be so close that any tests may not find any difference. But 3 years later those tests results could be extremely different.

The problem here is the “in service” part. It’s normally highly variable (so it either has to be carefully controlled (hard to do!) or you have to use large sample sizes.) Plus, you don’t want tires failing in service - for obvious reasons.

A retired bicycle dealer who used to participate in a bicycle forum, a very knowledgable fellow, lets his bike tires age 3 years before he uses them.

Why? Makes no sense to me.

I dont think I would worry about 2 years. 5 plus then I would worry .