The Great Tire Age Debate

[Dale & Mark Bruss]

Our first RV was a 7 year old motorhome. The front tires showed a little checking and we replaced them. The rear tires looked perfect.

When the tag tire destroyed itself and part of wheel area, we dropped the spare that had never been in the light of day, it was so bad, we didn't even try to use it.

As we got smarter, the spare on our trailer was changed for age along with the other tires.

We didn't carry a spare for the Volvo tractor, it is too easy to get a replacement on the road from tire service companies. The two times we had to replace a bad recap, we got suitable used replacements from the tire service company at a price far less that you would expect. After the second recap failed, we replaced with new tires from the tire service company and got a credit for the used tire we had just purchased.

On the motorhome, since we have tires that are basically the same size as commercial truck tires, we wouldn't even think of carrying a spare since tire services are available.
No use carrying a tire that is aging whether you are using it or not.

[Gordon Dewald]

Originally Posted by JohnRR

It is what it is, I've got over a 50 year back round in the automotive field and have never heard of a scientific test for tires aging out other than information from manufacturers saying to do so.

Tire manufacturers may have keyed on the best before date imprinted on all food stuffs. Makes me wonder as Green Tree sells goods that are past best before. A cake mix that is several months past the expiry date still bakes up and tastes OK.

I know the best before works wonders in our kids house holds. The day after the date the item is tossed.

[CampDaven]

Originally Posted by Mr_D

the estimate for my 8 tires and new SmarTire sensors is $6,763.48 through the FMCA Advantage program. That's $1,500 less than the same service at the same dealer and paying their regular prices.

I was using round numbers. FMCA and 8 tires taken into account. The financial message was about making sense of an earlier tire investment.
So, we both spend a lot, but not as much with the discount, and we both feel secure.

[Tireman9]

Originally Posted by Krash

Thanks for the inputs.

snip

Tireman9
Could you recommend one of these labs to me? I have no knowledge of polymer chemistry or Organic Chemistry, but I did read Goodyear’s recommendation on RV tire replacement, and they make no mention of age? So are you saying my spare tire should not be used in service because it is too old?

snip

By the way, a jug of milk taste bad after 4 hrs, 31 mins, at 70 degrees. I am just looking for someone to taste it and confirm.

Sorry it just isn't that simple. You are looking for a change in rubber structure at the molecular level. Unless you knew what the structure was when new you could not reliably come up with a relative age and age isn't what you really need to know.

Belt edge separations are the result of molecular level cracking and tearing coupled with the current tire loading. It would be entirely possible to have tire A to have more broken bonds than tire B but without also knowing the crack propagation rate of the compound in question you could not make any reliable prediction. Now if you can deliver about 10 tires of the same compound with differing "ages" we could start to accumulate a chemical background for that compound.
Next you would need test data where you run the tires on a known test and compare the failure rate. With all the above you might assemble a predictive line but that still would not answer your question about your tires or your usage because your usage is different than others.

Ballpark $20k to $100k to get the ranking + the cost of the tires.

Best thing to do is to go to a large tire dealer that sells your brand and design and starting at 5 years have the tires dismounted and inspected inside & out each year.

You might also consider having all your tires dismounted and sent to a re-tread shop for Holographic inspection. If they would tell you that they would accept tire #1,2,4,5 for retread but not #3 or #6 then you could just replace those two tires. Do the above each year.
Call local truck tire retread shop and ask if they can do Sherography and what would they charge you per tire.
Another link


Remember this is not a Go/NO-GO test only a NO-GO. Even if you pass the inspection there is no guarantee you will not have a failure in the future.

[flywithcoop]

Glad to hear you are replacing your tires. Just remember it is better to be SAFE than Sorry. IMO I would buy 6 new tires and I would not carry a spare tire. Are you really going to change a tire on the side of a busy highway? Do you have everything needed to replace the tire? I have emergency road service and the service will provide a tire if one is needed. On a recent call they brought two different brands of tires to make sure I would have the correct replacement. The repairman said the tire would cost the same as if I drove into the shop to buy it and have it mounted. They make their $$$ on the service call. I highly recommend emergency tire service.

[Dmiles]

Originally Posted by Davdeb1

If your tires look good, just make sure you inspect them and don't rely on that TPMS.

As I posted in another thread, I had a TPMS, and just never felt good enough about the operation of it to trust it, so I scrapped it in favor of a crossfire system for the rears, and old fashion tire gauge for the fronts.

So imagine my surprise the first time I put a couple hundred miles on the crossfire system, and the first thing I saw was red on both indicators! Red means plus 10%, but I've checked it with my pressure gage, and the 10% is when you first see the red. These were all the way into the red. When I checked them with the gage, they had gone from 100 psi to 123! I can tell you my TPMS never reported an this much of an over pressure situation.

My experience tells me TPMS is not the way I will be monitoring my tires in the future. I'll be setting my pressure so that it is just into the yellow, and just keeping a close eye on them.

[Dale & Mark Bruss]

Originally Posted by Dmiles

As I posted in another thread, I had a TPMS, and just never felt good enough about the operation of it to trust it, so I scrapped it in favor of a crossfire system for the rears, and old fashion tire gauge for the fronts.

When I first started, I used a high quality tire pressure gauge and had a tire thumper to check for a good ring from the tire at each stop.

Then a friend asked me how I check the tires at 55 mph. It would be nice if all road hazards happen when we are stopped but seldom do.

That is what a TPMS system does. It can warn you of many things and let you take corrective action before you become an unintended pedestrian when the tire failure puts you on the side of the highway. In my over 10 years, I have had a couple of instances where the low pressure warning gave me time to get to the next exit and a safer place to stop.

I had one event where a piece of road shrapnel flew up and cut the front tire of the toad. The alarm gave me time to get onto the shoulder while the toad tire was still reading 10 psi. Without the TPMS, my observation would have been the toad swaying all over the place and possibly damaging things.

I would never be without a TPMS.

[CampDaven]

Originally Posted by Dmiles

My experience tells me TPMS is not the way I will be monitoring my tires in the future. I'll be setting my pressure so that it is just into the yellow, and just keeping a close eye on them.

TPMS readings are only indicators. And you can trust the temperature and pressure differences they display, and the alarms.
Crossfire provides no monitorable underway indications.
The newer TPMS systems are much improved.
I used a tire gauge and thumper for too long. Too long enough to have a tire failure that severed a propane line.
I hope you will reconsider.

[JFXG]

Originally Posted by Dmiles

.....When I checked them with the gage, they had gone from 100 psi to 123! I can tell you my TPMS never reported an this much of an over pressure situation.........

In hot weather at highway speeds (~65) my tire's regularly gain about 20%. Steers go from 110 to about 130; duals go from 90 to about 110.


John & Diane, fulltiming since '12 02 DS40, FL, Cat, '04 Element NHSO RVM103

[rlott2k]

All you can do is a very good inspection, including inside the tread and inner sidewalls then trust your gut.

[NHRA225]

Originally Posted by rlott2k

All you can do is a very good inspection, including inside the tread and inner sidewalls then trust your gut.

Tire Inspection is useless if they are Aged out 6yrs or More !
Most of you Guys sit for months at a time- the Worst thing for tires there is !
Roll Em or loose them rings a big Bell ! I change mine at 6 yrs or 80,000 miles which ever comes first !
Michelin XZA3 Plus !

[CampDaven]

Originally Posted by rlott2k

All you can do is a very good inspection, including inside the tread and inner sidewalls then trust your gut.

That is a good process except for the "gut".
My gut can't tell me a pressure is dropping and a temperature is rising and I have under 5 minutes to pull over.
Folks, TPMS is a tool that can tell you there is trouble BEFORE there is trouble, maybe a catastrophe!
Remember when motors just quit, before there were warnings, or buzzers? I do.
Adjust, adapt, improvise, learn, accept, and improve your "tool box"!

[Krash]

I use, and trust, my TPMS almost completely. I can say "almost" because I check my pressures often with a good gauge. I also check my tire temps and bearing temps with a temp gun when I stop to stretch my legs on a long drive. I am certain that a TPMS can save your beacon.

I also have sending units on my trailer which is with me most of the time. We fulltime now, and my trailer has become effectively my garage. We carry our car, a boat, a Harley, my roll-away, two bicycles and some other necessities in it.

Last year, I towed my son-in-law's boat behind the MH. The boat trailer lost a wheel, and I didn’t even know it. I don’t know how long I was dragging that boat with only one wheel on. It must have scared the heck out of the people behind me. Anyway, I finally saw the boat in my side view mirror, and it was half way into the lane next to me with sparks flying. If that trailer would have had transmitters on it, connected to my TPMS, I would have known it when the tire blew, or the wheel departed the trailer.

I will never have a motorhome, or tow a trailer, that does not have a TPMS.

Just my opinion.

[rlott2k]

OP HAS tpms was asking about changing dated tires I believe.