How Hot Can Motorhome Tires Get?

[Xplorer]

A lot of discussions about tire pressures, weights, and Tire Pressure Monitoring Systems.

When monitoring tire pressure, and temperatures, how hot do the tires get while traveling down the highway before you should start to be concerned?

When operating at the proper PSI, and going down the highway, psi and temps rise.

A lot of information about psi, but couldn't find anything specific about maximum temperatures for tires.

Tire pressure and temps rise while moving. How hot before you stop and let them coooooooool?

[BillAdams]

There's no such thing as too hot while driving. Tires are designed to handle any and all temperatures you might encounter on any pavement at any speed (legal speed) with the proper inflation. Put the proper cold air pressure (the one printed on the side wall and adjusted by the manufacturers weight rating) and have a nice day. You do not need to over think this part of RVing.

[Xplorer]

I don't know the answer either.

So, when a tire blows, does it blow because of tread separation due to low pressure or does it blow due to high temperature as a result of low pressure causing the threads to separate.

How hot does a tire get before it blows?

If heat is not an issue why is it necessary to have temperature readings on tpms systems, why do folks buy infra-red temperature readers.

Somewhere heat and the temperature must be a factor.

Have a nice evening.

[tireman9]

Bill, Not sure if I completely agree with "There's no such thing as too hot while driving" as this is based on some assumptions that may not always be true.

Xplorer, Lets be sure we are using the correct terms so we are properly communicating.

The full answer is complex and I could spend an hour covering the details but here is a summary:

"Blowout" is a layman's term for a catastrophic tire failure. It is not an accurate description of the failure and without an accurate description we have little chance of taking the proper corrective or preventive actions anymore than saying "The guy is dead" doesn't help us to know if it was a gun-shot or of old age at 115.

A sidewall "Flex Failure" is normally the result of running significantly under-inflated at highway speeds for a number of miles. I would normally feel a 50% loss of air or more at 45 mph or higher for 20 or more miles but more air loss or higher speed will reduce the number of miles. In Steel sidewall tires the speed is less important than in Polyester or Nylon body sidewall as the heat generated from the flexing at speed can melt the polyester or Nylon but the steel will fail simply from too much over flexing even at very low speeds. When you see a failed passenger or LT tire with two sections of sidewall still attached to the wheel like this

that is most likely a Run Low Flex failure. A "Zipper" like this

failure in a steel body tire is also a Run Low Flex failure.

Now Tread Separations where the belts and tread separate from the body are normally the result of "old" tires with many hundreds or thousands of hours exposure to some overload and modest underinflation or long term exposure to solar heating (not under white tire covers) They can look like this

or this

I have a post on the long term effects of excess heat that can accelerate the aging process of rubber. This temperature effect is a major reason there is no simple answer on how old is too old for tires because the "tire age clock" is not constant like the calender but can be accelerated or slowed down depending on how the owner uses and stores the tire.

If you were hoping for a simple answer you should know that depending on speed and load the normal operating temperature of a properly loaded and inflated tire will be +10F to +60F above ambient. Some TPMS have a high temp warning set at 156F so if you need some number use that as "too hot".

[Xplorer]

Tireman9

Thanks for the great explanation. I think the 156 number may be what interests me.

What got me thinking about the psi and heat is when I installed the tpms last year.

The max psi for my Hankooks are 110, my inflation psi is 100. As I traveled during the hotter months I would not only see the psi rise (which I know is normal), and the temperature rise (which I also know is normal).

I know tire engineering is complicated and way above my pay grade. If tpms measures heat, and folks use the heat guns on their tires, it would logically seem to me, You should know what you are looking for.

If you are going to monitor temps, seems to me you should have an idea why you are monitoring, and the parameters. Otherwise, why bother. Oh, that's nice, my tire temps are registering 130 degrees.

Anyway, as you know when you are retired, you have plenty of time for deep thinking, ok, maybe not so deep.

After 38 years of Rv'n, and almost a dozen Rv's with 3 blowouts over those years, just getting around to this heat question,,,,Must have been in the slow class, and didn't know it. I think only 3 blowouts isn't too bad, and 2 of those happened on the same RV within 2 days of each other. Needless to say, all tires were replaced. It has been a learning curve. OOPS, catastrophic tire failures.

Thanks again for the great explanation.

obtw, great pictures, also.

[tireman9]

Tireman9

Thanks for the great explanation. I think the 156 number may be what interests me.

What got me thinking about the psi and heat is when I installed the tpms last year.

The max psi for my Hankooks are 110, my inflation psi is 100. As I traveled during the hotter months I would not only see the psi rise (which I know is normal), and the temperature rise (which I also know is normal).

I know tire engineering is complicated and way above my pay grade. If tpms measures heat, and folks use the heat guns on their tires, it would logically seem to me, You should know what you are looking for.

If you are going to monitor temps, seems to me you should have an idea why you are monitoring, and the parameters. Otherwise, why bother. Oh, that's nice, my tire temps are registering 130 degrees.

Anyway, as you know when you are retired, you have plenty of time for deep thinking, ok, maybe not so deep.

After 38 years of Rv'n, and almost a dozen Rv's with 3 blowouts over those years, just getting around to this heat question,,,,Must have been in the slow class, and didn't know it. I think only 3 blowouts isn't too bad, and 2 of those happened on the same RV within 2 days of each other. Needless to say, all tires were replaced. It has been a learning curve. OOPS, catastrophic tire failures.

Thanks again for the great explanation.

obtw, great pictures, also.

Glad you found the info helpful. As I said if you monitor your pressure the temperature is just an interesting number. Next time your traveling and it is warm note the tire temperature then if it starts to rain watch how fast the temperature drops. But keep your eyes on the road. and don't be distracted by your TPMS.

[JamesEdwards]

May 5, 2014

I think you should check tire temp. Check all tires at all stops when driving time is longer than a hour. If a tire is higher than 35 Deg.different than the rest you are most likely going to have a problem or you have a low tire (pressure).

If you have a temp meter, how much time does it take?

HAVE A GREAT Cinco de Mayo.

[manholt]

Tireman.

I'm looking forward to your seminar in Redmond. Have a safe trip!

[tireman9]

May 5, 2014

I think you should check tire temp. Check all tires at all stops when driving time is longer than a hour. If a tire is higher than 35 Deg.different than the rest you are most likely going to have a problem or you have a low tire (pressure).

If you have a temp meter, how much time does it take?

HAVE A GREAT Cinco de Mayo.

James, If the a tire is properly inflates the temperature will probably be between +30 and +60F above ambient depending on speed, load and aerodynamics.

I can tell you from personal experience that the hand held IR temp guns that many have, can not locate and properly measure the localized hot spots in the base of the shoulder slots. Rubber is not like metal where the temperature will be relatively uniform. Tires have very localized hot spots as seen in THIS post.

If you are going to make any effort to monitor anything it should be the pressure and TPM will do a much better job than occasional check during driving breaks.

[gaylemarlowe]

Just got back from our long trip and we had a whole new set of Michelin 295x80R22.5 put on during the trip. Coming back out west we ran into 95-100 degree ambient temps and I checked tire temps periodically with the infrared gauge during the whole trip.

Tireman is correct: we saw temps ranging from 20-25 degrees higher than ambient in wet weather, to 60 degrees higher than ambient on hot days, dry hot pavement.

And I can tell you from personal experience, when you put your hand on a tire that is at 165 degrees, you will swear it is in the process of melting off the rim!! It is HOT!!