What does "MAX" psi on tires mean?

[Tireman9]

There seems to be a lot of confusion about the "MAX PSI" number on the tire sidewall. That PSI number IS NOT the highest pressure a tire can tolerate. Undamaged tires do not "Explode" if you exceed that psi number.
This may help. Read the words so you understand what the "MAX PRESS" is referring to. The "AT" is an important part of the statement. Some tires may not have the word "at" in the statement.

The "Max psi" is the pressure required to support the "Max Load" which is also stated on the tire sidewall.

We tire engineers test our designs at well above the pressure your tires would get to under normal circumstances.

Tire pressure only increases by about 2% for each increase in Ambient temperature of 10°F , so even with an increase in temperature of 90°F or 100°F, you should only see a pressure increase of 45 to 50 psi. If you have weighed your RV and consulted the industry tables on Load & Inflation and always inflate your tires to the PSI indicated in the tables for YOUR load, you will probably only see a pressure increase of 20 to 25%. If your TPMS is reporting a greater increase, you need to confirm your load and your cold inflation pressure and your travel speed which in an RV should never exceed 75 mph.

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Related note: I usually recommend that people add 5% to the Minimum inflation found in the tables, to lower the probability of driving while the tires are underinflated.

 

[jleslie48]

I've always kept my tires at max psi, and I seem to get a blowout around 8,000 miles. However, those are with bias tires. I just replaced my tires with radial ones. I'm hoping for better results. This is a trailer, I don't understand why they can't make solid tires. There is no ride issue as no one rides in the trailer when its being towed.

 

[Tireman9]

I've always kept my tires at max psi, and I seem to get a blowout around 8,000 miles. However, those are with bias tires. I just replaced my tires with radial ones. I'm hoping for better results. This is a trailer, I don't understand why they can't make solid tires. There is no ride issue as no one rides in the trailer when its being towed.

Solid tires are heavy and expensive PLUS you would be speed limited to about 10 MPH max as a solid tire develops too much heat.

 

[Gottasmilealot]

It is exactly what it says...

The maximum pressure of inflation for the tire cold. Yes, it might be able to be more, but this figure allows for expansion of the tire when heated. There's no reason to inflate it more because you should not be going over the maximum rated low capacity anyway. More is not always better.

 

[wesleyfurr]

I have always kept my trailer tires at max inflation as well. I figure they run cooler and less rolling resistance. Yes, they might wear out more in the middle, but I've never come close to using up the tread, age always gets to them first.


As for the tires failing at 8,000 miles - how old are they at 8k miles? And how close to their max capacity? From what I have seen and read, 5-7 years is about all you want to run your tires...and if they are closer to their max capacity, they are probably going to fail more quickly as well. Hopefully not an issue with a Sunline, but I know some newer trailers are pretty long and heavy sitting on a single axle.

 

[jleslie48]

The tires are less than 5 years old. I've had 2 blowouts in 8000 miles. If anything I run the tires low, but I'm pretty sure they were at max. I repack the bearings every other year.

 

[wesleyfurr]

The tires are less than 5 years old. I've had 2 blowouts in 8000 miles. If anything I run the tires low, but I'm pretty sure they were at max. I repack the bearings every other year.

Ouch...seems like they should hold up better than that! What is the trailer weight compared to the tire load limit?

 

[jleslie48]

Ouch...seems like they should hold up better than that! What is the trailer weight compared to the tire load limit?

the tires say 1300lbs. my 1976 mini-micro comes in at 1250, but with the gear I'm probably towing 1700. I was under the impression that the 1300 was per tire, and as such, since I have 2 tires, My max load limit is 2600.

 

[flashpuddin]

Waste system

I have an 2006 Sunline Model 2753, the 3" waste valve (black water) flange is cracked. I found this out when I thought the valve was leaking and while disassembling the system. The "T" has a fixed 1-1/2" flange to bolt the valve to and the 3" flange is a swivel, this is the one that is cracked It's very easy to service, besides draining the black water tank. Is there a known repair, perhaps a split plate? Or must I replace the "T" assembly, and if so where can I get one. Thanks

 

[jleslie48]

FWIW, I ripped all plumbing out of trailer years ago. Never regretted it. Now I ripped the kitchen out too.

 

[flashpuddin]

I was trying to post a question , this site is a little confusing.

 

[wesleyfurr]

the tires say 1300lbs. my 1976 mini-micro comes in at 1250, but with the gear I'm probably towing 1700. I was under the impression that the 1300 was per tire, and as such, since I have 2 tires, My max load limit is 2600.

I would think that should be well more than sufficient. If anything, the load is less than that as some amount of the total weight is on the hitch.