Replace tires due to age

[Cressida]

I have a 20+ year old Firestone tire that I have saved and will be using as soon as I need a "new" tire on one of my cars. It spent most of it's life as a spare in the trunk of an old Camry and I don't think it has ever been on the ground.

I intend to take pictures of the date code and post here whenever I get around to putting it in service so you can get a real time test of how it goes (and those in the immediate area can keep a good distance

)

 

[KitaCam]

Storing a tire in the trunk has always been concern to me...so I include the 5th tire in the rotation with the other 4 every 18 months...

 

[FL-400S]

I just got done replacing some BFG Touring TA from Sams club. They had a fair amount of cracking after only 3 years installed and 31k miles. A big disappointment. I had to have the same ones replaced on a different vehicle due to cracking after just a few years. I finally learned my lesson and stopped buying BFG tires from Sams.

I had pretty good luck catching Michelin on sale at sears. Check the website or just wander in and if they are motivated they may find you a deal. I got a better deal at one sears than another, so maybe shop around.

 

[diver1972]

Originally Posted By: Cressida
I have a 20+ year old Firestone tire that I have saved and will be using as soon as I need a "new" tire on one of my cars. It spent most of it's life as a spare in the trunk of an old Camry and I don't think it has ever been on the ground...
I found a barely, if ever, used full-size Goodyear Integrity tire in the spare tire compartment of a '99 Camry I just bought. It's 15.5 years old per the date code. When I stopped at Discount Tire to get all the pressures, including the spare, properly set, the tech refused to even touch the [censored] thing as if it had some communicable disease. He firmly stated that 10 years is the maximum age that they'll service.

I planned to replace it because it's just too risky, even for a spare that'd likely be used for a very short distance. After reading this thread and TR's write-ups, I'm absolutely replacing it...with a new-to-me used one since I can't justify spending $50 for a brand new one that only might ever be used.

Originally Posted By: KitaCam
Storing a tire in the trunk has always been concern to me...so I include the 5th tire in the rotation with the other 4 every 18 months...
I like this idea. I'll start doing this when I buy another set of four five tires.

 

[diver1972]

Here's an interesting related excerpt about on-vehicle spare tire storage from the NHTSA:

Quote:
...the results support the hypothesis that spare tires could degrade while stored on the vehicle. This is a particular concern when coupled with the inflation pressures of full-size spare tires at retrieval. Over 30% of the passenger and light truck tires at the spare tire location had inflation pressures below the T&RA Load Table minimums. A recent study by the agency projected that more than 50% of passenger vehicles will still be on the road in the U.S. After 13 years of service, and more than 10% will still be on the road after 19 years. For light tucks, those figures go to 14 and 27 years respectively. Since few consumers replace their full-size spare tires when replacing on-road sets of tires, full-size spare tires have the potential for very long service lives. This elicits the logical concern that older full-size spare tires with possible degradations in capability may see emergency use while significantly underinflated.

 

[xfactor9]

Originally Posted By: CapriRacer
As I explained above, a 100% nitrogen filled tires is subjected to a 3.1 psi oxygen pressure from the outside.

A 100% air filled tire at 30 psi is subjected to 6.3 psi oxygen pressure from the inside. Even at 35 psi, the oxygen pressure is only 7.4 psi.


Does this mean that for long-term storage, it's better to place the car on stands and deflate the tires?

 

[CapriRacer]

Originally Posted By: xfactor9
Originally Posted By: CapriRacer
As I explained above, a 100% nitrogen filled tires is subjected to a 3.1 psi oxygen pressure from the outside.

A 100% air filled tire at 30 psi is subjected to 6.3 psi oxygen pressure from the inside. Even at 35 psi, the oxygen pressure is only 7.4 psi.


Does this mean that for long-term storage, it's better to place the car on stands and deflate the tires?


Sort of.

When a tire gets inflated with air, the oxygen permeates out faster than the nitrogen. What that means is the percent oxygen inside the air chamber gradually goes down.

Adding air to boost the pressure back up, increases the oxygen content, but only a little.

- BUT -

If you completely deflate a tire, then refill it later, the air inside the air chamber is now back up to the starting percentage. There's a point where doing this has a more detrimental affect than merely leaving things alone.

I tried to find a paper that Dr. John Daws wrote up - and I think it is here:

Nitrogen Inflation for Passenger Car and Light Truck Tires

He also has a spreadsheet that help:

Tire Air vs Nitrogen Permeation Simulation

The key issue that is missing here is the affect oxygen has on a tire that is NOT inflated. But Dr. Daws did make one important point and that was deflating a tire then refilling it (like you would do with winter tires) was one of the worst things you could do. You would be repeatedly adding fully oxygenated air back into the air chamber.

If I am reading this right, there is almost no scenario where deflating a tire for long term storage is better.

Plus, the way you asked the question, you would either want to get the car off the tires, or roll the vehicle forward a foot every month to prevent flat spots.

Then what about inflating the tires to 60 psi with air to prevent flat spots? That also seems counter productive from the tire degradation point of view.

I think the bottomline is that nitrogen can slow down the rate of deterioration, but not a lot. If you can get nitrogen for free, use it. If not, don't worry yourself about it.

 

[CapriRacer]

Oh, and I was pointed to this in another forum:

The Affects of Varying the Levels of Nit...est Performance

In this paper they document the fact that oxygen goes INTO the air chamber on a 100% nitrogen filled tire.

But there was also an interesting tid bit. They tested some tires with various test conditions - and the only failures they got were with a 50% N2/ 50% O2 mix, oven aged, and only on 3 brands - Cooper Sumitomo, and Hankook - and in all 3 cases, both tires tested failed. I take this to mean that there is something different about the way these 3 brands react to oxygen (and by extension, aging) compared to the other brands tested. Hardly definitive, but interesting nevertheless.

 

[Traction]

Originally Posted By: CapriRacer
Oh, and I was pointed to this in another forum:

The Affects of Varying the Levels of Nit...est Performance

In this paper they document the fact that oxygen goes INTO the air chamber on a 100% nitrogen filled tire.

But there was also an interesting tid bit. They tested some tires with various test conditions - and the only failures they got were with a 50% N2/ 50% O2 mix, oven aged, and only on 3 brands - Cooper Sumitomo, and Hankook - and in all 3 cases, both tires tested failed. I take this to mean that there is something different about the way these 3 brands react to oxygen (and by extension, aging) compared to the other brands tested. Hardly definitive, but interesting nevertheless.

Very interesting, detailed article. I will keep using N2 in my tires as I have for 10 years now, with positive results, although small, it does make a difference.

 

[datech]

Would using Armour All or some kind of tire 'polish' keep them from oxidizing?

Just an anecdote-- I had a Motorcycle I bought in 1980 with Cheng Shin tires and used them a bit over 25 years. Mostly stored inside when not used. I finally replaced them at 15 K miles and I had a bald strip on the rear with some cords showing. I didn't use them on really long trips but did go on the highway pretty regularly for maybe an hour or so at a time. I always kept them well inflated.

 

[Boss302fan]

Originally Posted By: Cressida
I have a 20+ year old Firestone tire that I have saved and will be using as soon as I need a "new" tire on one of my cars. It spent most of it's life as a spare in the trunk of an old Camry and I don't think it has ever been on the ground.

I intend to take pictures of the date code and post here whenever I get around to putting it in service so you can get a real time test of how it goes (and those in the immediate area can keep a good distance

)


Hopefully when it blows, you only hurt yourself...

 

[NormanBuntz]

I also found some major tire makers recommend 6 years as a max tire life. That includes time sitting in a hot warehouse before you buy them or sitting in a cold winter garage at home. My Michelin LTX tires started to degrade after five years, long before the tread was worn out.

 

[Boss302fan]

Winter storage you should inflate your tires to help prevent flat spotting... Putting up on jack stands can ruin your springs.

 

[JMHC]

Originally Posted By: Boss302fan
Winter storage you should inflate your tires to help prevent flat spotting... Putting up on jack stands can ruin your springs.


This is what I do. Placard says 30 psi which I use for driving, and in storage I go up to 40 psi close to the 44 psi max inflation pressure to prevent flat spots.

I got such a good deal on new tires I went ahead and ordered some BF Goodrich G-Force Super Sport A/S. I want to be safe and have the ability to drive my car spiritedly without worry.

 

[Tosh]

Originally Posted By: Boss302fan
Winter storage you should inflate your tires to help prevent flat spotting... Putting up on jack stands can ruin your springs.

It might ruin YOUR springs if it's a poorly designed car. Can you imagine a car so weak that it destroys its own springs from just lifting a wheel?!
My Honda product's owner's manual actually recommends storing the car on jack stands...

 

[Boss302fan]

Originally Posted By: Tosh
Originally Posted By: Boss302fan
Winter storage you should inflate your tires to help prevent flat spotting... Putting up on jack stands can ruin your springs.

It might ruin YOUR springs if it's a poorly designed car. Can you imagine a car so weak that it destroys its own springs from just lifting a wheel?!
My Honda product's owner's manual actually recommends storing the car on jack stands...


OK. All I know have is years of experience and having numerous collectors tell me to not put up cars on jack stands for an extended period of time. Its your car do what you want. LOL... I'm talking about collector cars, not HONDA's. LOL.

 

[CapriRacer]

Originally Posted By: Boss302fan
OK. All I know have is years of experience and having numerous collectors tell me to not put up cars on jack stands for an extended period of time. Its your car do what you want. LOL... I'm talking about collector cars, not HONDA's. LOL.


I can see issues with springs falling off their perches, and damage when a shock gets fully extended. But I can also see merit to getting the load off the tires. I guess the best way is to have the vehicle stored such that the tires are barely in contact with the ground.

 

[jimbrewer]

I don't know where the answer lies, but I realized recently that with my 8K per year mileage I need to go out of my way NOT to get high mileage tires--weird.

 

[TrevorS]

I'm less than that so went with Pirellis as they have an unlimited time on treadwear warranty.