How long should tires last before they dry rot?

Well guys, I took the rig to our Michelin dealer today. The guy there took pics, measured tread depth and wrote down the VIN and mileage of our Chateau. He called Michelin and they said they would give me my choice of Michelin LTX2's, BFG's or Uniroyals, since they own all three brands, for 80% off retail price. I was stoaked. I chose the BFG's as I did not want to take a chance on the Michelin's although they may have been perfectly fine.

Kudos to Michelin for standing behind their product. I was prepared to fork out $1500 for new boots, but as it turned out it will be less than $500 mounted and balanced with full warranty.

SAR Tracker

Thanks for the info on determining the age of tires. I knew there was a code and was getting ready to research it. You saved me the trouble. And the pictures really helped me a lot!

I've always replaced my MH tires at 6-7 years regardless of how good they looked. However, last year we bought a used 2005 motorhome with an unknown history. Looking at the tires (three different brands) I've determined the steering tires are week 46, 2011. Rear left are week 1, 2005 and cannot tell rear right as I cannot find the DOT code. I have an appointment Monday to install 4 new tires on the rear axles. Even though the current tires look okay, we're not taking a chance.

I reaplaced six Michelin tires on our Tioga 26Q, two of them were only 4 years old but already had medium depth sidewall cracks. I hadn't been covering tires but I do now. Tires that are over 5 years old should be inspected for sidewall cracks and replaced if cracks are significant. I have read that RV's need to be driven frequently at highway speeds to circulate "lubricant" in the rubber to get best tire life. When a newbie to RV's, I had overaged rear dual tire come apart and the flailing steel belt damaging holding tanks etc. Why risk it?

ron.dittmer wrote:
I agree...that is crazy for 3 year old tires. I would discuss with the tire company before the seller.

Did the previous owner live in desert heat? Maybe a steady diet of 120 degree weather is the culprit. Still this should not happen that soon.

We live in the high desert, but do not get really high temps like say, Arizona. In fact we have very few days over 100, maybe 4 or 5 per year.

pnichols wrote:
Rush,

Those are terrible cracks in your photos above. You should get some $$ back from Michelin somehow someway.

What Load Range are they?

What pressures do you run them at versus their maximum allowed pressures?

What is the weight of your truck camper?

Have you been using Aerospace 303 on them every 30 days?

By the way, Michelin may just about be done producing M&S tires. Their main LT tire line appears to be M&S2. This new tire line now uses different materials for the sidewall plies.

They are load range E, and the owner told me he always checked the pressures, although he never said how much he set them at. Also, it is not on a truck, it is on a 25ft Class C, that pulled a motorcycle trailer and always under cover when not used. I seriously doubt weight is a factor as the fronts are cracked too, just not as bad as the rears.

According to the pamphlet that came with all the manuals we got, Michelin does NOT cover dry rot. But, I may take it to a local dealer and see what they say. It definitely sucks for sure. I did not plan on having to put tires on it.

I have no idea what Aerospace 303 is, remember I just picked up this coach yesterday.

Oh, and my name isn't Rush, that was just a little humor in my profile.

I agree...that is crazy for 3 year old tires. I would discuss with the tire company before the seller.

Did the previous owner live in desert heat? Maybe a steady diet of 120 degree weather is the culprit. Still this should not happen that soon.

Rush,

Those are terrible cracks in your photos above. You should get some $$ back from Michelin somehow someway.

What Load Range are they?

What pressures do you run them at versus their maximum allowed pressures?

What is the weight of your truck camper?

Have you been using Aerospace 303 on them every 30 days?

By the way, Michelin may just about be done producing M&S tires. Their main LT tire line appears to be M&S2. This new tire line now uses different materials for the sidewall plies.

Guys, I just got off the phone with the seller, who is an extremely stand up guy. I told him about the dry rot and he said he never noticed it as the rig was always fully covered. He said he would split the cost with me on new tires for it. I took a few shots of the 10k mile, three year old Michelins. Remind me NEVER to buy them....

Right rear


Left rear


Left front

pnichols,

In support of your theory, our first motor home was very tiny, built on a Toyota chassis. The chassis and house combined weighed only 3600 pounds. On trips we added an additional 600-700 pounds. Total weight on trips never exceeded 4500 pounds. It had 6 "D" rated tires which after 12 years, still looked decent with only minimal tire cracking. I sold the rig in 2007 with those 12 year old tires with roughly 50,000 miles of use. Had I kept the rig longer, I would have gone a couple more years before buying tires.

It was stored indoors when not in-use, in the same bay my PC does today.

I too am not convinced I should be replacing tires so often. Our 9200 pound rig today with 6 "E" rated tires is not quite like our previous rig, but still has lots of vehicle weight-to-tire rating margin. But unlike yourself, I don't max out the tire pressure at 80 psi, solely to keep the ride softer.

The Old Rig


The Weight


The 12 Year Old Tires

It has to be the WEIGHT on RV tires that is the prime culprit in destroying them prematurely ... nothing else explains "dry rot" to my satisfaction.

Here's my "proof": I had the same Cooper tires on my PU truck here in (relatively) dry California a LONG TIME ... at least 12 years with no apparent "dry rot" at all ... only tread wear. I replaced them this year due entirely to tread wear. This truck has always been kept outdoors under a LOT of sun. But here's the big-proof-gotcha ... the tires were two sizes over stock size, so their weight carrying capacity was well over what the truck had on it for 98% of those tires' life. In other words, the tires were way under-loaded day after day year after year. What other thing could their extreme life be attributed to?? UNLESS ... Cooper (back then - in at least in those tires) used some super formula for the material it in it's tires ... which I doubt.

What weight does to RV tires is make them flex a lot when under way or when sitting not being used. That's why I always use high pressures in my RV's tires regardless of how hard it makes the RV ride ... so that this high pressure will keep tire sidewall flexing/bending to a minimum under the high loads that an RV is continuously applying to it's tires.

I'm open to any other explanation that makes sense as to why my lightly loaded pickup truck's unprotected tires never dry rotted for such a long time in a 10-20% RH climate ... as compared to heavily loaded RV tires.