Tire age... the real scoop

Some of you remember I picked up a low-mileage little-old-lady car :  1997 Lincoln Mark VIII.  The couple that drove it had quit driving many years ago and it sat most of the time.  The result is that I have like-new sneakers... that are dated 2013.  It sat in a garage and only got about 10k miles in the last 10 years, so they don't show any cracking or UV damage.

I'm wondering what the real scoop is.  How much of tire aging is environmental (HCs, oxidation, etc) vs UV damage?

The look new, no cracking, and have nearly all their tread.  I would hate to ditch them if I don't need to.

Likewise, I would hate to see one delaminate and beat the E36 M3 out of your pristine bodywork, or cause a crash, etc.

I'll run a winter tire to 10 years if it's still got tread because they don't get hot. I would not run a tire past 8 years old in August. And I'm frugal. 

UV damage is a big part of it, outgassing and oxidation are also factors though...if they look fine I'd try driving on them and keep an eye out for any new cracks forming.

See how much traction they haven't.

A while back I had the opportunity to drive a 430 mile Mercury Sable.  It was stored inside since new, essentially, and the tires had no cracks.  They were also so slidey that it was comical.  

Are they quality tires? Have you driven it?

There is a chance they have been sitting on the same spot they could develop a "flat spot". Once rolling again could be prone to separating. 

Many years ago, I had a Z-24, and several Fieros as parts cars for my race Fiero.  I needed to get to a concert about an hour up the road, and had cords showing on the front tires of the Z-24.  Took the best looking two tires off one of the parts cars and down the road I went.

On the way up the Interstate, a Dodge Daytona (fwd) blew up about three cars in front of me.  When I hit the brakes, both those tires separated their belts, and I had a thumpy ride.  Luckily, my exit was the next exit.  The ride home sucked though, going through towns on the state road.  Took much longer.

Beware tires that LOOK good.

Pete. (l33t FS) said:

See how much traction they haven't.

 

A while back I had the opportunity to drive a 430 mile Mercury Sable.  It was stored inside since new, essentially, and the tires had no cracks.  They were also so slidey that it was comical.  

That's a great point. I put a pair of "old but looked good" tires on the front of my E12 and it would lose front turning grip at around 0.5G, and the they would lock at very low decel. Never again. Old tires are the devil.

I bought my e36 with low mileage, garage kept, but 9 year old, PS2s. They would spin through 2nd. I quickly replaced them.

I had to put my spare on my truck years ago. It was a Michelin and I joked with a friend that it was the best tire on the truck( I think I had some Geolanders on it at the time).  It don't recall the age but it about 8 years old.

The "Best" tire came apart at 70mph going across one of the bridges that span Tampa Bay. Wiped out the passenger side of my bed.

Keeping in mind it had a hard life under my truck, I would still beware of 10 year old tires. Especially if you hit highway speeds.

The volatile compounds that make tires grippy outgas and go away over time no matter how they are stored.

They will have less traction than new tires and will fail state inspection if that is a thing where you are.

I use 7 years as my rule of thumb but YMMV.

My first thought, 1977 Lincoln? Who cares, it probably can't reach highway speed, or stop properly anyway.

Then I saw 97.  Don't be a tightwad.  New tires are great.

Streetwiseguy said:

My first thought, 1977 Lincoln? Who cares, it probably can't reach highway speed, or stop properly anyway.

Then I saw 97.  Don't be a tightwad.  New tires are great.

A 1977 Lincoln is the last thing I would want hockey puck tires on.  Been there.

Trent said:

The volatile compounds that make tires grippy outgas and go away over time no matter how they are stored.

 

They will have less traction than new tires and will fail state inspection if that is a thing where you are.

Those same compounds make the tire flexable so that it doesn't come apart while in use.  How quickly they'll outgas depends on a variety of factors and other than rolling the dice and seeing what happens when you drive the car there's really no way to tell if your tires are still good at more than twice the recommended age.  Personally that's outside of my comfort range.

In reply to Curtis73 (Forum Supporter) :

Cease the moment to get your Vouge Mustard and Mayos.  Only $320 each from Tirerack

frenchyd said:

In reply to Curtis73 (Forum Supporter) :

I disagree with most here. I've used. very old tires without distress or problems.  Yes they do tend to  slide around - a lot!  
   Now the fact that I haven't experienced  the disasters  others report may have to do with our cooler climate, a more gentle driving pattern, or better voodo?  
  I believe the horror stories given are sincere.  
However to me things are not that cut and dried.   Back in 1962 I raced a straight 8 Buick in hobby stock.   The tires were at least 20 years old, they did have some minor cracking,   maybe original.  

Bias ply tires are a different animal. Still a bad idea, but completely different construction methods.

Would you trust a condom that had been in someone's wallet 20 years? even if it looked new?

Some old-tire testing that we did a little while ago, complete with data and everything: Testing the New Yokohama A-008P–And, Yes, Tires Do Stop the Car.

TL;DR: The old tires performed well–right up until they didn’t. 

As someone whose had pristine looking tires come apart my advice is change them.

https://uk.motor1.com/news/681177/triumph-tr7-tyre-blowout-caught-on-teslacam/

frenchyd said:

In reply to Curtis73 (Forum Supporter) :

I disagree with most here. I've used. very old tires without distress or problems.  Yes they do tend to  slide around - a lot!  
   Now the fact that I haven't experienced  the disasters  others report may have to do with our cooler climate, a more gentle driving pattern, or better voodo?  
  I believe the horror stories given are sincere.  
However to me things are not that cut and dried.   Back in 1962 I raced a straight 8 Buick in hobby stock.   The tires were at least 20 years old, they did have some minor cracking,   maybe original.  

As my dad pointed out to me on more than one occasion, just because you've gotten away with something in the past doesn't mean it's a good idea.

I had new-but-ten-year-old takeoff tires on my Sentra.  (Was restoring a BMW 2002 that they put new tires on before parking it)  They were scary.

I had new 10 year old Eagle STs on my first RX-7 - the last STs in Ohio, apparently.  They glassed over at 50F like you wouldn't believe, were marginal any other time.

These made me form my opinions on tires.  Now, I scrap winter tires after the second season.  The performance drops off noticeably even by the end of the first season, after the end of the second season they may as well be all-seasons.  I generally choose summer tires that trade off wear for performance because there's no sense in having a tire that ages out before it wears out.

I had a set of very low Michelin Pilots that had full tread and great looking sidewalls, but I eventually discovered some very stealthy cracking deep in the grooves between the tread blocks. 

Most of the car manufacturers say to replace tires at the 6 year mark as do most tire manufacturers. Michelin and Continental say replace them at ten years. Personally, any tire over 5-6 years old is suspect to me. Obviously, use plays into this, but I don't think you want to change a tires in your nice clothes.