Age of your tires

I only run bias ply on my trailers because they don't tear up as much if they should fail. I try to not have trailer tires older than six years. They are stored outside. My indoor stored, locally run vehicles I limit to ten years if they are holding up. I replace a lot of tires with 3/4 tread life left though.

 

I'll give you credit for creativity.

Planned obsolescence of tires is definitely a fable. Think of what a liability that could be. Really, the recommended life span by tire manufacturers is conservative due to potential liability. The potential liability of your theoretical 6-year life span tire failing at an engineered 7 years would be massive, and something that could be litigated frequently. You've touched on the actual issue, but you're a bit off sir.

What we're really talking about in tire replacement is degradation, but what makes it complex is that there are various types of degradation at play. Rubber when exposed to oxygen slowly degrades, losing strength and flexibility and becoming harder (your tires grip less over time). So there's degradation of the rubber along with degradation of the chemical bond between layers of the tire, the steel belts and the rubber, etc. Those are all impacted by a variety of factors.

Temperature: A tire that sits on a hot asphalt parking lot in Arizona daily versus an enclosed concrete-floored building in my backyard in Alberta is going to see very different levels of degradation. Heat cycles from driving, burnouts, rubbing, or sitting can all impact how quickly the components of a tire degrade and how that impacts the life of the tire.

Also factors are UV, humidity, exposure to ozone, applied weight, etc. You would need to control all of those factors to "control the breakdown" of the bonding components in the tire. There are far too many factors to control that.

What does have a big impact on tire life is changes in the chemicals and compounds used due to things like supply chain issues, increased cost of raw materials (so they find cheaper options), and new advancements in technology and research. Supply chain issues in polymers occur daily, and substitutions occur all the time.

Back to degradation, when you see weather checking on the outside of your tire that's degradation of the rubber, but generally doesn't indicate a structural breakdown of the tire and sometimes is more cosmetic. The degradation you can't see, breakdown of the bond between sections of the tire and the belts and the rubber, are more likely to be what will cause a catastrophic failure. If you can see a crack forming on the outside, you should be able to catch it. Failures on the inner bond create situations like separated tires.

So no, there isn't a conspiracy trying to shorten the life of the tire, but there are many factors that contribute to the life of a tire. If you can control the storage conditions and keep your tires out of the elements, you should be able to easily get more than 10 years from them. If your rig sits outside in extreme temperatures all year, you will more likely need to replace your tires in less than 10 years for safety. Every car has different weather, storage, and use conditions. Manufacturers are using a very conservative one-size-fits-all approach that applies to the average user, and usually that's not us.

More from Hagerty here: Old tires might not be as dangerous as you think—if you store them correctly - Hagerty Media

 

I just sold a set of 14" AR TT's that were on my PU when I bought it. The tires are 20 years old but have never seen the street, just paint rollers their entire lives. Still have nubs on the tread surface!

I told the guy that bought them that I ought to put a knife through each sidewall, but I left that for him to decide. No cracks, but I wouldn't run 'em.

 

I don’t understand !
Are you saying that you are prepared to risk your life for an icecream………must be good icecreams……..

 

I'd risk my life for ice cream. Repeatedly.

 

Heck my wife would make me walk 3 miles uphill both ways naked in the snow for ice cream

 

I don't think I would be driving anyplace with 35 year old tires, I change out my tires at a max time frame of 6-7 years old.

If the ice cream place is on the way to the tire shop, I suppose I could be distracted for a bit longer before the new tires got put on. But then I'm not driving down the highway at 70 mph on those old tires either.

There is a cure for needing to replace old tires with a lot of tread still on them.... Drive the car!
I usually replace the nearly worn out tires at about 5 years old (with 40K to 50K miles on them). Works out well for me.

 

Nice to see Hagerty at least tentatively trying to debunk this.... and it's mostly bunk. This has been brought up here multiple times, but we still get chicken littles who come on here and exclaim 'if your tires are old you're gonna die!' I'm not going to expend the effort to re-type this yet again, so I'll provide links below. But I'll summarize the pertinent bits.

All of this came out of the Ford Explorer/Firestone tire debacle in the 90s. Tires were exploding, people were getting killed and lawyers were all over this. Congress noticed and authorized the National Highway Traffic Safety Administration to investigate. As most of these failures were in the sun belt, they selected Phoenix Arizona as the test site, the US metro area with the highest average daily temps in the US. The NHTSA released an interim report which I downloaded and read. Over 100 pages, with some extremely interesting nuggets in the appendices. I had this saved, but lost it in a hard drive crash. All you can find now is the final report which was carefully scrubbed of any conflicting facts, but still worth reading. Anyway, on to the nuggets...

Tire aging. It's agreed that heat ages rubber. What's not mentioned is when graphed, it's an exponential curve. Remember, they picked a worst-case scenario, which is where the six year 'recommendation' came from. Drop your average daily temp by 20 degrees, and the ageing rate is reduced by roughly 75%. Where you live can make a big difference.

Accidents. The NHTSA also searched all available accident reports for three years from all 50 states, and admitted they couldn't find even one documented case of an aged tire being the cause. Road hazard was #1, underinflation was #2.

I think underinflation is by far the main cause of tire failures (why else do newer cars have pressure monitors?) after road hazards, and we're probably guilty of contributing to it. As someone who grew up with biasply tires, adjusting tire pressure was the time-honored solution for best tread wear and ride comfort. Because biasply flexed all over, any heat build-up was spread out over the whole tire. That's not the case with radials. The tread belts are there to prevent that flex, so most all flex is in the sidewalls. When typically we would drop tire pressure when fitting oversized tires, that's not a good idea with radials. I personally won't run less than 26 PSI in any radial, 28 to 32 is better. That is what got Ford in trouble on the Explorer; to improve ride quality, they specified a low 22 PSI inflation pressure and the added heat at the sidewall/tread junction killed the tire over time.

Technical - Check your tires on your car! | The H.A.M.B.
Technical - Got 5 year old tires? | The H.A.M.B.
Technical - Tire deterioration / When should you buy new ? | The H.A.M.B.

 

I'd agree that a lot is how much they are exposed to direct sunlight and weather. It's usually the trailer tire or tire on the seldom driven only used when you need to truck that gets hit with direct sunlight all the time that blows when you are going down the road.

Personally I'd have more faith in a 30 year old bias tire with a tube than a ten year old radial that still looks new. Not that I am a big bias fan but they don't seem to come apart like older steel belt radials do.

 

What @Crazy Steve said! Tire gospel.

Being in the tire biz I had a friend who was in the Product Services dept of BGSTN:FST at that time. He was assigned to run the tests and gather effect data during that time and examine all the tires submitted for warranty.

Ford had spec’d a lower inflation than the manufacturer BGSTN/FST and actually put it on the door jamb sticker.!
So you load Mom and the kids and all your s**t in your Explorer and head out on your vacation out West. Many were found to have had the roofs loaded with camping stuff also. You diligently checked(or not) your tires before you left.
NO radial passenger tire could be expected to survive 120 + degree pavement, 70+ mph sustained speeds, overloaded and under inflated! The heat buildup was unforgiving, and the primarily rear tires suffered “catastrophic failure” at speed, causing loss of control and subsequent crashes.
Firestone spent millions, running that size tire 24/7 to take care of the replacement need, pre-emptively replacing many not yet failed tires.

And as Firestone and Ford had a OE relationship started by Harvey and Henry back in history things were stinky. Goodyear actually got to furnish Ford OE tires for a while.

What the hell does this have to do with our hobby? YOU are responsible for the choice of tire, its maintenance and its service life. Always err on the side of due diligence and rigorous service. Learn how to identify potential problems. And pray that the moron you’re meeting has done the same. The tire failing is the end result of one or more events leading up to that point.

 

Don't forget what the tire is parked on if it sits for very long. Dry concrete is good, but wet/damp can leach chemicals that will degrade rubber. Dirt is even worse. The organics in soil can rot a tire faster than you think.

 

Oh no! I drive cars with four wheel drums, single reservoir master cylinders, and 8 year old tires. I’m doomed.

 

That makes 2 of us Lane!

 

Yes there was.... Ford was trying to meet a specific ride quality level, and the initial tire Firestone sent over was rather heavy, too heavy according to Ford. So they requested a redesign with a weight reduction. Firestone complied but cut one corner too many. They might have got away with it if Ford hadn't specified such a low inflation pressure. Bottom line, they both fucked up...

Remember, this whole investigation was triggered by the car/tire manufacturers as they were terrified that this would open the floodgates for class-action lawsuits. They needed something 'official' to protect them, enter the NHTSA.

I used to but lost it in a hard drive crash. And these aren't 'claims', this was clearly stated in the report. I'm not recommending anything except maybe take what we're being told with a grain of salt; make up your own mind. All this was in an 'interim' or 'preliminary' report (I don't recall the exact title). I searched for it later but found only the final report with most of this info removed. I suppose you could make a FOI request to the NHTSA and maybe turn it up, although the final report can be illuminating if you do a bit of reading between the lines. The appendices in this report detailed everything that was tested and how; what tires brands/sizes, who did the testing and the results of it. As examples, Goodyear and Firestone (?) did all lab testing. They artificially aged the tires in ovens then subjected them to machine load tests. The NHTSA wanted real-world data, and rather than wait for tires to age naturally in use, they contracted with local tire shops to purchase the 'aged' target tires (still serviceable) off of customer cars by offering really large discounts (free in some cases?) towards new tires. A lot of this testing was very technical, and I won't pretend I understood all of it or even most. But I could read the conclusions... and one thing stood out. You'd think there would be failed tires right and left under hard testing. Not so, while there were some, these were declared as 'statistically insignificant'.

At the end of the day, two things came out of all this. The first one was they did note that at six years (in the worse-case Phoenix environment) some chemical/structural degradation was noted in the tire carcass. They were careful to also note that this wasn't an automatic precursor to failure, just a 'concern'. This led to the NHTSA 'recommendation' of having your tires checked at that age. They still allude to that as this quote from their current site you linked to shows... 'Tire aging is a greater concern in the more southern parts of the Sun Belt states'. Yes it is. But it's not where I live...

I suspect this wasn't quite what the tire manufacturers wanted. Probably anticipating windfall sales, they likely hoped for a definitive time with a 'its required legally' excuse. As a sidebar, Dunlop dropped their expiration date on their bike tires to only three years but had to take it back when their distributors howled that they'd end up eating some of the slower-moving sizes. Now the last thing a tire manufacturer wants to tell a customer is the tire he bought will become dangerous and maybe kill him on some magical date, so some tire makers said nothing, some made recommendations of 'checking', some deferred to the vehicle manufacturer's recommendation, or some combination of the above. Time durations were also all over, generally between 6 and 10 years.

They neatly solved this problem. By shifting it to the tire retailers, the tire/vehicle makers are off the hook, they sell more tires. The retailer screams about 'liability!!' and you're SOL. 'Slow leak? Sorry sir, the tire is too old'. 'I can't mount those snow tires, too old'. Some of these guys are mercenary asshats. A few years ago I was in buying a couple of tires at one of the big chain outfits with my grandson. An elderly woman drives in with an obviously low tire, says she thinks she's getting a flat, can you help me? The guy looks at the tire (checking the date code) and announces, 'it's too old to fix'. The tire has at least 50% tread. She asks if he could put the spare on. Nope, it's too old also; I can sell you a new tire, well actually two because they have to be replaced in axle sets. She looks like she's going to cry. I tell the grandkid to go put on her spare for good deed. He gets a sloppy kiss and a tip, I get black looks from the tire guy. I stopped a few months ago in my OT recently purchased convertible with a low tire at another local tire shop and asked if they could put some air in. The guy comes out to look, I can tell he's looking for the date code. He finds it, it's almost new so he airs it up. What sort of song and dance would I have got if it wasn't? Sheesh...

The other thing to come out of all this? The Tire Pressure Monitoring System now featured on all new cars. I have mixed feelings about these. Another expensive gizmo to go wrong (and they do) but on the other hand they do work. Although when I change to my four studded snows on rims on my Expedition, I have to see that damn light all winter...

Retrofit kits are available, those of you with tire age paranoia would find these useful I would think...

 

I've read through this entire thread. Thanks to all who commented.

I have an altered roadster drag car that I run at two - maybe three - vintage races a year. As such, it sits for long periods of time between events. Indoors. Out of the heat. I noticed some minor sidewall splitting and debated running the nearly new looking slicks at this years races.
Nope. Its getting new slicks before my next race thanks to what I've read here.

 

lol. I mean I’ll probably take it 6 miles to the ice cream place once to make sure the bugs are worked out of the car before putting the new tires on.. I have a slam type bead breaker and tire irons so I can operate as a tire shop in my garage.

 

I never took or thought about tire age as I've never had a set of tires last me 5 yrs. I drive too much and too hard sometimes for them to last that long.

UNTIL I had a very good friend of mine with a beautiful 68 camaro that I had worked on numerous times. The tires were name brand radials that were at least 5 to 6 yrs old on it. Less than 8 for sure.

Anyway we had a big car show one weekend about an hour away. He takes his 15 yr old daughter and 17 yr old son with him. While running down the highway he passes a car, hits about 70 mph and a rear tire comes apart. The car goes into the ditch and back out and then starts rolling over and over.

My friend lost his daughter that day and his son in paralyzed from the neck down. My buddy has never been the same, the guilt he holds has marred his entire life and the only reason he is still alive is to take care of his son. Had something happened that his son had past too there is no doubt in my mind My buddy would have ended it long ago...

An investigation by the state showed the tires were aged and that's why it came apart. BTW the car was always kept in a garage and the tires looked fine.

After that I paid more attention and noticed that other friends and buddies had older tires come apart on them but not to the extent of damage caused above..

So yes now I pay attention and heed to tire age. A town cruiser I'd say 5 to 7 yrs max for me, hiway driven and no way I'm driving on a tire older than 5 yrs no matter how "good" it looks.

It only takes once to suffer the loss My buddy did and lives thru everyday that tires are very cheap compared to the guilt he feels, justified or not...

...

 

Race tires aren't generally designed with longevity in mind.... good call.

I knew a few guys many years ago who tried running super-wide Indy car tires on their street cars. They didn't hold up well.

 

A few things I know for sure about tires is, the older they get, the harder the rubber tread becomes. The harder the rubber becomes, the less traction the tire provids against the road surface. In my experience I can feel the difference the hardened rubber and lesser traction as the tires age. I can feel the difference after about 3 years, but it continues to deteriorate more rapidly with each passing year. Old tires spin and skid more easily then they do when they are new, they just don't have the grip they used to have.
The current tires on my coupe are 5 years old. Just today, I noticed the tires chirping when up shifting at a range they never would have, even last year. This happened when the road surface is warm, clean, and clear (a V6 5 speed is not a race car). When you add just a cold road surface (outside temps below 60 or so) to the hardened rubber, traction becomes worse then when the roads are warmer. The cooler weather allows the poorer traction to show more. Generally speaking, less traction is not a good thing.
The tread depth is getting thinner (still good tread above the "safety bars") but that too really shows up more when the roads are wet. I will continue to monitor the tires on my coupe, but next year it will get new tires. The tires will be six years old, and still have "legal" tread, but someone else can take a chance on them. I'm not going to.

I've seen tires come apart, just the damage they can cause to a car's body far exceeds the the cost of new tires. You all do as you please, and I will do what I do. Just don't come crying to me if one of your old tires explodes and kill the fender, I won't feel sorry for you.

 

There are a lot of tires in the world. Auto manufacturers mandate what they want, and they get it. Do any of you know if you find date codes on aircraft or tractor tires? Why or why not? I know of aircraft and tractor tires that are 20+ years old and still going strong. Different operating environments. load limits, and all types of other variables. But tire manufacturers know what they are selling and how the tires are and aren't affected by age, temperature, and host of other variables. Tire manufacturers are a part of the issue, but the automotive industry sets the standards for what goes on cars. Just like some old gasoline is still fine after sitting years, some old tires protected from the elements are still fine after years. Ask yourself how that can be if you think tire degradation is strictly a normal occurrence.

 

Believe what you want. Keep in mind that radial tires have been around since the '50s in Europe and since the early '70s in the US. It wasn't until the Explorer/Firestone fiasco that 'tire age' became a thing and it was only explored then because they didn't want to admit they had screwed up.

And yes, I do routinely run my tires beyond those age limits with no issues. I've had a half-dozen or so catastrophic tire failures in the 60 years I've been driving and most of them could be clearly attributed to road hazards. There were three that weren't. All were less than six years old, all had tread separation. The common denominator? All three were Les Schwab tires. I don't buy those anymore....

 

Thanks @Crazy Steve for reporting the facts.
On neither side of the debate I can claim seeing an Explorer dive into the median.
It comenced to barrel roll and leave a trail of merchandise of considerable volume.

 

Unpopular opinion apparently, but I happily run tires well older than me.

the fronts currently on my roadster are Atlas Plycrons, they were NOS, tucked away in two separate garages before I got them, with the paper tags still on them (my guess is pre-1970)

the rears are bias ply Vouge tires, which I can find no info on, but are probably from the same era.
they were also NOS, the old guy bought them cause they looked cool and had them on the wall in his basement.

no joke, both sets of tires were softer than some new tires I've had, and they ride better than some new tires I've ran on the car.




I'm not afraid to run them.



Honestly though, I check my tires. I feel them, and I check the air pressure.

I drive a car with no safety features to speak of, so I take checking things seriously.

.

 

I'm not sure if it's a crossply-vs.-radial thing, really? My own experience suggests that tyre compound formulations changed radically somewhere in the '80s. I remember being astounded at the level of grip provided by that first set of Goodyear NCTs c.1990, compared to the best I'd known before. It was night and day. I never experienced such a dramatic improvement again, despite going at times to arguably far more serious rubber since.

It's like a steady slow rise in tyre performance up to the '80s, then a sudden jump, and then another slow rise at an improved level thereafter. It tracks with my view that the automobile basically happened, technologically, in the '20s, then in the '50s, and finally in the '80s, before dying c.1995, though with each wave adding less than the previous wave (arguably actually subtracting stuff after 1995). Thus the '80s gave us AWD, the waste gate, decent tyres, and little more.

So obviously a lot of research had gone into the modern tyres. But that would have been subject to stated goals. The engineers would have been chasing something, and that would have been informed by an idea of the anticipated way vehicles and hence tyres would be used. Increasing grip — especially lateral grip — was important; improving tread life, expressed as distance, was important; reducing rolling resistance was important. If the price of this were an increased tendency to deteriorate over time, then so be it. The expectation that cars would increasingly be used more intensively over shorter periods of time, accumulating greater mileages but being scrapped sooner, made that factor less important.

That this would be more beneficial to some than to others is incidental — but at the level of structure not trivial.

The question which interests me most is, what would truly durable high-performance tyre tech look like? A grippy 100-year tyre is possible, and a better world might have incentivized it. The alternative is a flexible manufacturing process that'd enable tyres to be made or remade in whatever oddball size you want. I'd be even keener to see that.

 

Bias plies can go longer because nylon and rubber mate together and move together better than rubber and steel cords of a radial. The relative movement of the cords with the rubber is what causes problems dealing with heat/underinflation flex. I'm also convinced the quality of rubber today is inferior to 20 years ago.
FWIW, I had a never used, always bolted to it's spare rack, trailer radial explode while sitting. About 10 years old.

 

Hello,

One of the most difficult things was getting rid of tires that looked new, but had wear left on them. When my wife and I bought a 327 powered 1940 Ford Sedan Delivery, we overlooked the individual details, as we knew we had our own ideas ready to go into the project. It looked finished, but there were tons of things necessary to make it into a safe handling hot rod that stopped well and did not shake upon trying to stop.

The fairly new looking tires were suspect, so as we started our “fix” we tried to work with them. Re-balance, and align, etc. but, that did not work, along with other necessary suspension repairs. So, we took it to a friend’s shop and he suggested to get a new set of better tires and he would do what was needed to make it track straight and stop well. It took him several weeks for the complete front end repair, replace and get a set of new tires. But, it wasn’t just a set of new tires, those new tires got the tire shaving process and it certainly looked as if a couple of 1000s of miles were on the floor of the tire shaving shop. Yikes!

But upon inspecting the other tires, despite being new, they were brand name, quality tires, but were not absolutely round. What? Tires not round? As simple as it seems, yes, tires aren’t always round and they will wear unevenly despite balancing and alignment. So, before spending money on high quality tires, true the tires. All of us will get more miles running true round tires, balanced and aligned...YRMV

Jnaki

So, out go the fairly new looking tires and off to the tire shaving shop with the new 4 tires. They all got shaved and then back at the friend’s alignment shop, got rebalanced and aligned the correct way. Add this to the already replaced suspension parts, it became a great daily driver and cool handling, safe hot rod. Once all of this was done, the 327 powered 1940 Ford Sedan Delivery ran and drove so well that my wife chose it as “her” daily driver before I could grab the keys. First come, first served… ha !!!

Yes, as those old/new tires were thrown into a pile at the shop, it was disheartening to see it done. But, tires are the only thing between you and the road. Bad tires, bad results and no longer safe at any speed. This rule applies to all cars, new and old. You certainly would not take your new car tires off and put on a set of tires that were sitting around in your garage, would you?

 

Here's my last comments on this. First, those of you that live in 'the southern half of the sunbelt' as noted by the NHTSA should definitely factor the 'six year' rule into your tire decisions as those conditions were the subject of the study. But those of us that don't live there and have less hazardous conditions, that rule is inaccurate. But alas, Pandora's box has been opened. In a perfect world, further studies would be done to accurately determine regional differences, but no one is willing to spend the money or administer it (plus the negative impact on tire sales). Then you have the can of worms with owner care. Should a truck/trailer/RV that sits next to the shop in the weather between its once or twice a year usage be treated the same as a collector car carefully stored indoors? Of course not. Then there's the sham 'inspections'. When this all started, the tire/vehicle manufacturers were loath to admit that their products could become dangerous at some point. So, they 'recommend that you have the tire inspected by a qualified tire technician for suitability'. All 'inspections' I've ever seen consisted of the 'tech' checking the date code only and pronouncing the tire unsafe. Sure...

Last, the variations in 'expiration' times. These are all over the map. I see guys mention 5 year dates, even shorter than the NHTSA data which was supposedly a worst case. Just a method to generate more sales, or are they selling sub-standard tires that don't last longer? And in what I see as a tacit admission of regional differences, the local chain stores have 'generously' extended the time out to ten years. Customer blowback? IMO they're shorting us at least two years of service life, likely 6-8 given the local conditions coupled with proper tire care.

If your cardiologist operated the way these tire stores do, if you went in for heartburn you'd come out with a pacemaker.

 

Let me guess... trailer tires. I don't know what's up with those, but they seem to have way more issues than regular car/truck tires. And you did the right thing. I inspect my tires and won't run any that show signs of distress. But I won't throw them away just because of age.

 

This thread is yet another great example why anyone seeking any serious information should never, ever read, let alone rely or trust anything posted on internet forums like this one.
So much utter BS & irrelevant nonsense, including uniformed opinions & wives tales, posted by so many with apparently no real interest in actual & relevant research.

As far as I'm concerned, anyone driving on public roads with tires older than +/-6 years (soft compound, high performance/- speed tires 3-4 years max) from the date of manufacturing, not when they were bought or installed, doesn't deserve (my) respect as a true automotive enthusiast, i.e. real & serious car guy/gal.
I couldn't care less or feel any empathy if these idiots themselves get hurt or their vehicles fncked up by their own ignorance/stupidity, but I don't appreciate when that stupidity endangers the safety and well being of other road users, including me and all those I care about.

And some wonder why I rarely attend car shows or participate in forum discussions about them.