Does your tire says "MAX PSI 80 psi." or something similar?

 My answer is that while those words or similar may be on the sidewall, those words are NOT to be taken literally as an instruction because those words are in reality only PART of an important phrase.

In reality your tires more likely say something like "Max Load 2500 pounds at 80 PSI Max Inflation". Of course different vehicles will have different size and type tires but we are looking at some general guidelines here.

Do you see and understand that the actual information the tire company is telling you is that the tire has a maximum load capacity of 2,500 pounds when it is inflated to 80 Psi? Most people understand that the load capacity of a tire is controlled and limited by the inflation in the tire, so this phrase is telling us that the load capacity of the subject tire will never be greater than 2,500 pounds even if you increase the inflation pressure

The loads and inflation are published in industry standards books such as the US Tire & Rim Association. Almost all tires made for sale and use in the US will follow the industry standards book AKA "TRA".

 I believe that the RV company engineers either have copies of the books or at least copies of the applicable pages.

 As always, you need to remember we are ALWAYS talking about the "cold" inflation which means when the tire is at Ambient air temperature and has not been driven or in direct sunlight for the previous couple of hours. If I ever talk about the warm or hot inflation that will be made obvious in that post.

Every vehicle has a Certification Label. This image is from a Class-A RV.

The specifics of this individual label are not important as you should have captured a nice, sharp picture of the label for your RV.  Class-A has the label usually near the driver's left elbow, Class B & C and LT have the label in the driver door jam and towables (TT and 5th wheel trailers) have the label on the outside, driver side, toward the front of the trailer.

The label states the Tire Size, and the recommended inflation if it is a passenger car. If it is an RV it will give the GAWR, Tire Size, Tire Load Range, and the inflation required to support the GAWR. Passenger car and pick-up truck inflation is arrived at after years of testing and evaluation of different tire designs from different manufacturers at different inflation that balance the requirements on a long list (hundreds of items) from the vehicle company. These requirements include Force & Moment test results and fuel economy plus dozens of detailed ratings within each category for Ride, Handling, and Noise. Car inflation is a "Recommendation" from the engineers at the car company aimed at giving you the performance they designed into the car.

I have never heard of RV companies evaluating tires. It seems that they generally look for the lowest-cost tire that can provide the load capacity required by law. This usually means for towables that the tires would need to be inflated to the level required to deliver the max load capacity. A few RV companies are selecting better tires with Nylon Cap Ply but you need to pay attention.

The inflation number on a tire sidewall is the PSI needed to deliver the Max Load rating stated on the tire. Normally tire load capacity is increased with an increase in inflation and that would normally mean you would increase the inflation, BUT since the tire was selected for its max load capacity as stated on the tire sidewall, the inflation that will deliver the highest load capacity for that tire is the "MAX infl" which is NOT the highest inflation the tire can tolerate.

Yes, the wording can be confusing but the wording was not selected with the average user in mind.
Motorhomes are built on chassis built and designed by vehicle manufacturers so the tires on Motorhomes will many times have inflation on the label that is lower than the tire max because the tires were evaluated and selected by the vehicle chassis manufacturer.

Many towables are built with minimal capacity for additional "stuff" but many people load their RV with no thought to the load capacity. This is why the data shows that over half the RV on the road have one or more tire or axle in overload. This is a major contributor to tire failures and why there are so many RV trailer tire failures.

Too often on RV forums, people do not pay attention to what type of vehicle is being discussed A Passenger car (or 1/2 tom Pickup) or a Motorhome or a Trailer (5th wheel). These three completely different types of vehicles require three different guidelines and inflation information. This failure to be specific with the vehicle type is why people get confused.

 

How to avoid Tire Valve Stem failures

 I received a question:

"I pull a 27 foot travel trailer with dual axles and carry two spare tires and I needed both of them. One is on the bumper and the other is on an under-mount. I do not use a TPMS because we had one and had issues with valve stem leakage.'

I have responded to similar questions and provided links to one or more of the dozen posts I have made in this blog on the topic of "Tire Valves".

I guess that some folks did not check these resources, so here is what I hope is a comprehensive reply to the issue of tire valve failure when TPM sensors are attached to standard rubber stems.

If you had problems with valve stem leaking, then it is most likely that you were using the "low-cost" rubber stems intended for passenger car tires, like a TR413 as seen here:

TPMS external sensors screw on the end of the stems, and while they are not very heavy, that extra bit of weight does result in vibration, which can result in the fatigue failure of the rubber stem as seen here.

Here is an example of the movement of a rubber stem with an external:flow-thru" TPMS.

 

There are some rubber valves called "Hi-Press" as they are "rated" for 80 psi.
Here is a short video showing a FAILED TR800HP valve stem.

[video width="406" height="720" mp4="https://www.rvtravel.com/wp-content/uploads/2025/08/3-HP-rubber-valve-fail-due-to-TPM-sensor.mp4"][/video]

Here is a comparison of a few different stems.

From the left, we see a TR800HP that some call "Hi Press", next a TR413, then TR416 and TR435, which are both "bolt-in" stems and will not vibrate and fail due to flexing. Note: I placed pennies under 3 of the stems to raise the shoulders for them all to the same level for the picture. I wanted the comparison to be as if the valves were at the same level in the wheel.

Auto Zone has TR416 bolt-in stem Part # 20128 SKU #582043 at $6.99 for 2.

O'Reilly stores carry Part # 15-4559-2   1" chrome Tire Valves" - Fits Rim Hole Diameters of 0.438" and 0.625 Inch. The list price is $7.49 for 2.

Many other auto parts stores carry similar "bolt-in" stems

Some Aluminum wheels have a deep recess for the valve, as seen in this picture.

I understand that some Airstream RVs and some Ford vehicles have this type of bolt-in valve. It is a  "Dill-VS-902-W" and can be found with a quick Internet search for $2.50 to $6.50. I have read reports that some "Discount Tire" stores have or can get these Dill stems.

NOTE: There are 2 different hole diameters in the wheels. Most ST tires and LT tires will come on wheels with the smaller 0.375" dia hole.  The larger 0.625 gasket will not fit in the smaller hole. Both parts listed above show both sizes of rubber grommets. Select the appropriate size for your wheels.

This shows the two different grommets, so its pretty hard to get the wrong one. It is a light press fit or even "slide-in' fit into the hole in the wheel.

Special Caution. All of these "Bolt-In" valve stems need to be tightened to 25 - 45 INCH- POUNDS, so don't over-do it.

I believe that if you switch to "Bolt-In" stems, you will avoid the vibration failure of the stems. I always use "bolt-in stems" in my race cars and on my RVs and trailers and have never had a stem failure.