boonie c4

My tire mechanic upon completting my tire balance show me the manufacturing dates of my tires "front tires 2004, rear tires 2005" he said that the tire compound begins to deteriorate after 5 years of useage and expouseur to the elements and for safety reason they should be replaced even though i have over %90 tread remaining and they have less than 15K on them he said that this makes no difference once your tires have exceed 5 years of useage their not safe to drive on. My question: Is he correct? or is just trying to sell me a set of tires?

SJW

There are far too many variables involved in this subject for it to be distilled down to such a simplistic statement as what you were told.

The tread compound will tend to harden with age, but how much it does this depends upon many factors.

If your car is street-driven in a sane manner, not track-driven, and the tires still grip well (especially on wet pavement), and the tires are showing no visible signs of deterioration, drive on and forget about it.

The Michelin Pilot Sports that are presently on my '94 have been on the car since I bought it in 2004, and I see no reason as of yet to replace them.

Live well,

SJW

QCVette

He is partially correct. Tires do age. The rubber gets harder and they can fail.

The time frame for when they are unsafe has several opinions and can vary based on how the tires have been kept. Most seem to suggest somewhere from 5 to 10 years. I think I read somewhere about 7, but it depends on conditions.

My opinion is that at 5 years the tires are losing performance, but are probably not unsafe. If you want best performance then you need to replace them, but for street driven not track driven like SJW stated I would run them a while longer.

pcolt94

I usually hear of numbers of 7 years, as said there is a variety of factors. The older tires will often have accelerated problems at high speeds where additional heat is generated. Especially in the summer where the pavement can be hotter than 125* it can really heat the tire up and that is the worst time a problem can occur.

I can tell you I had to replace 4 tires on my trailer with almost perfect tread. I forget exactly how old they were but probably at that magic number. First one just started to separate. The I drove it and another came apart on the way to the tire dealer. These were special trailer tires, not cheap regular tires. Not garaged so the elements were at it.

radar502

I think it's your life span is what to look at. I had a set on on a 77 24,000 miles looked good drove around block boom back drivers side. The tires that came on new... I going slow just to checking out vett ..If going to drive on then after five years need to be replaced. I know people drive on older ones .Just took off a set off a little car I drive around parts chasher tires about 5-6 years old 20,000 miles maybe had cracks in them starting to dry rot . Like I said need to look at your life span... You are driveing a Corvette right ? Sometimes you might want to go realy fast.. If anybody tells you that 5-6 years old tires on a vett or any thing else ok .. BS.. I deal with old cars an old tries every day.. Time to start looking at some new ones...and check the date on the new ones the new ones they might be 5 or 6 years old... Don't take chances over a buck or two..

cv67

Mine are 4 yrs old and starting to deteriorate.

Chuck Tribolet

It's also a function of how much sun they get. Tires on
a garage queen will last longer.

87 vette 81 big girl

It is a very loose rule of thumb how long tires will last or when they should be replaced.

I would say somewhere between 4 years to 10 years.

It is sunlight UV rays, potholes, under recommended air pressure inflation of tires, & 0zone/ Ionized Oxygen that kills tires early on.

Ozone is likely the most destructive.
It will crack anything made of natural or synthetic rubber in a short period of time.

Ozone is generated by anything with High KV AC or DC current present nearby.

BR

oldalaskaman

I used to run BFG's on my tow truck in alaska, after bout 5 years thay would develop bubbles, I switched to michilin X's and didnt have any more issues. has lots to do with the tire compound, tire maker, they started putting nitrogen in them to slow that process down.

Bobzilla

Don't forget air temps. HP Summer tires will deteriorate FAST in sub-freezing temps. the more heat cycles they see like that the faster they will go. Thankfuly, I don't have to worry about time on my tires. I need rears in 4k miles.

hooked073

The US is just about the only country that does not reguire it's tire manufactures, dealers, installers to remove tires older then 4 years from the shelves and not sell them. There are several major dealers in the us now that will not sell or install a tire more then 4 years old. Many people have won law suits even though the US has no law, but they knew the dangers involved. There were dealers buying out dated tires out of country for cheap but that has been put to a holt for the most part.

T. Wayne Nelson

How in the hell do you get a set of tires to last more than a year on the backs and two on the front

PLRX

Proper Alignment

the blur

5 years in the sun.
15 years in the garage.

like trailer trailers. you need to cover them, or they dry rot.

don't forget, your spare tire is 20 years old.

93Rubie

Depends on how they are used stored. For example I recently bought a set of tires from tire rack.com they have a date code in 2008. So they are brand new 3 year old tires. This being said, tire rack stores them at exactly the right conditions and tires can be stored like this for quite some time. Once in use however I would say about 5 years on the short end and maybe 7 or 8 on the high end. It all depends on what you are doing. Any kind of high speed use I would replace them sooner than later. For tooling around or for a garage queen leave them on for a bit longer.

The bottom line is do you want to risk tire failure at speed? The older the tires the higher the risk. It is that simple.

hooked073

Goes a lot deeper then being in the sun how they are stored how they are stacked. Goes beyond what can be detected by the eye.

bdanyluk

I have a 1996 Impala SS also.

I recently replaced the stock tires about 3 years ago. (yes, recent and 3 years ago sound weird)

So that means they were on the car for about 13 or 14 years. Always garaged.

No cracking or serious age indications. Got about 47,000 miles out of the stock BFGs.

mseven

bottom line is the fresher the rubber the better the performance.
However mfg.'s send tires that have build dates on them that are that old that have been in their "warehouse" and are considered "new". Some of this is due in fact to popular sizes/type selling quicker and others sizes/types not being sold as fast. I went through this with BFG's KD and KDW, and had Discount tire keep sending them back until I had sets with a more current build date (285's and 315's). Personally I don't care how they were stored, if I'm buying new I don't want to see that they were built 5 years ago.
Unless buying specific race tires were the mfg. makes a set number of sets per season, have I seen build dates being more current. For example the MT ET's I have now were built 3/2011.

dizwiz24

I am a chemical engineer working for a major tire company....

The company I work for (surprisingly) does not believe in a policy of tire age limits but rather takes the stance 'it depends'.

Tires get brittle and harder as they age be@ause the vulcanization process keeps occurring (albeit very very slowly) building more crosslinks. Though, an ultra high performance tire tends to have a slower rate of this phenomena. Still a loss of performance could be the result due to this phenomena. The higher temp environment the tire is stored in accelerates this.

Ozone damage typically affects sidewall. Sunlight, exposure to ozone (welding, electrical discharge, etc.). There is an ingredient called 6ppd that neutralizes this reaction, but once that ingredient has fully been reacted, it cant continue to provide protection. If youve ever seen brown on your sidewalls, dont wash it off. Thats 6ppd doing its job. Any ozone cracks deeper than about a 1/16" is cause for removal.

Waxes and other ingredients (appear white) provide static ozone / oxidation protection of sidewalls on a tire that is sitting.

Inflating with nitrogen will slow down the oxidative aging of the internal components as the oxygen-less nitrogen diffuses through the tire. Especially in that critical belt ending area in the shldr.

Keep that in mind for a garage queen. Nitrogen has a
benefit then in that case.


If you are worried about a tire, you could try taking it to a commercial bandag or michelin retreader and see if they will run it through shearography and look for internal tire separations like they do for truck tire casings before a retread.

dizwiz24

I also forgot to add.

Uhp tires, like ours, also typically have volatile resins in them that can essentialy diffuse out (evaporate) under the right conditions, too many heat cycles, etc. The purpose of these resins is for traction.