I have had some tire problems in the past so I know a lot of the do's and don'ts. So I have this question which I probably know the answer but I will throw it out here anyway. The last 2 years we have wintered in Florida and this year in Arizona. Being from Minnesota I left in the cold and I made sure that my tires had 80 psi in each tire like it should. I did not check the tires until today and all 4 had 90 psi in them. I checked the tires today because we have been sitting for 3 weeks now and it needed to be done. I did not check the tires until now because it was still plenty cool as far down as Lubbock TX. I know there is a difference in warmer climates as well as elevation too. But should I be checking the tires more often on a trip (provided they are cold) than I have been? I did put all the tires back to 80 psi.Thanks,Bill

I will always check before leaving for a trip.. once on the road I will check at each rest stop but NOT adjust air out... They will have more pressure in them from being hot.. As long as the tires are at the proper operating temp when you leave,, your good to go.

Do you have 80psi in your tires because that's the max air psi rating for the tire? Or did you weigh the rig and determine that 80psi was the pressure you needed for your load?

Tires should be checked each morning before traveling for the day. If you're not traveling no need to check them unless they are low enough to APPEAR low. There are a LOT of things other than temperature that will have an effect on your tires (barometric pressure and altitude) to name two.

On any of my trips fro a cold climate to warm, I will check air preasure every morning there is a 15 degree up surge in temp. I don't worry to much about mountans.

In response to spindrift and anyone else who is interested, when I was having my tire problems the last 2 years I was getting a lot of help in this forum and the overwhelming response was: first always check tires cold and second, if it says 80 psi, then that is what you put in. Besides, I did weigh my rig on a CAT certified scale and I am within about 700 lbs of maximizing the weight limit of cargo put in the coach. I plan to stay within those numbers too.thanks,Bill

tire air pressure | Good Sam Community

36 Replies

Me_Again
Explorer III
Jan 22, 2014
FastEagle wrote:
I've posted a couple of references with very specific information about tire pressures in this thread. Some people are blinded by what they read when it doesn't agree with their way of thinking. I cant make amends for that. In one, NHTSA says the vehicle manufacturers recommended tire pressures are the CORRECT tire pressure for your vehicle. In the FMCSA regulation vehicle manufacturers are DIRECTED to set the recommended tire pressures and display them on the vehicles certification label. The FMCSA document is standard document that all vehicle manufacturers MUST abide by.

On another note: Certification labels are mandatory items and must be displayed on all new vehicles. Certification labels can only be changed by a dealer prior to the vehicle's first sale. After that only a certified vehicle modifier or the vehicle's manufacturer has the authority to alter a certification label. Auxiliary labels are allowed for after market additions such as plus sized tires requiring different recommended tire pressures. NHTSA has issued a number of vehicle recalls for certification labels displaying incorrect information from it's manufacturer. The penalty allowed to be assessed by NHTSA for manufacturer misinformation is quite severe and can run into the millions.

FastEagle

We are all consumers, not manufacturers! Chris
FastEagle
Explorer
Jan 22, 2014
I've posted a couple of references with very specific information about tire pressures in this thread. Some people are blinded by what they read when it doesn't agree with their way of thinking. I cant make amends for that. In one, NHTSA says the vehicle manufacturers recommended tire pressures are the CORRECT tire pressure for your vehicle. In the FMCSA regulation vehicle manufacturers are DIRECTED to set the recommended tire pressures and display them on the vehicles certification label. The FMCSA document is standard document that all vehicle manufacturers MUST abide by.

On another note: Certification labels are mandatory items and must be displayed on all new vehicles. Certification labels can only be changed by a dealer prior to the vehicle's first sale. After that only a certified vehicle modifier or the vehicle's manufacturer has the authority to alter a certification label. Auxiliary labels are allowed for after market additions such as plus sized tires requiring different recommended tire pressures. NHTSA has issued a number of vehicle recalls for certification labels displaying incorrect information from it's manufacturer. The penalty allowed to be assessed by NHTSA for manufacturer misinformation is quite severe and can run into the millions.

FastEagle
Me_Again
Explorer III
Jan 22, 2014
Michelle.S wrote:
Chris, any chance you just answered your own question regarding Cardinal vs Montana. Since you state you have the optional 16" tires vs the std 15s, is it possible that Cardinal put the wrong placard on your RV, the pressure sounds like the correct pressure for a 15" D tire?
If it does state the correct tire size, please disregard this post.

Placard list LT235/85R16E tires. OEM were Kenda Klever LT china bombs. Kenda gave me 110 each to remove them when trailer was 8 months old. Before they failed, based on experiences others were having with them.

Glossy list ST225/75R15Ds! My trailer is a LX model(29WBLX) that had 99% of the upgrades rolled into one package!

And I installed Michelin XPS RIBs! :B:B:B

Like FE we run pretty heavy as a snowbird home each winter. And I normally run with full water as that tank is in the very back! I raced RC trucks in Arizona, and took up RC airplanes, so just about every storage area is packed completely full. Got an extra 100 pound just in 5 steel carcass tires.

Knock on wood!!! I have never had a tire problem in about 50K miles.

Chris
Michelle_S
Explorer III
Jan 22, 2014
Chris, any chance you just answered your own question regarding Cardinal vs Montana. Since you state you have the optional 16" tires vs the std 15s, is it possible that Cardinal put the wrong placard on your RV, the pressure sounds like the correct pressure for a 15" D tire?
If it does state the correct tire size, please disregard this post.
Me_Again
Explorer III
Jan 22, 2014
FastEagle wrote:
Recommended tire pressures must be set by the vehicle manufacturer. Positive direction to set those recommended tire pressures found on your trailer’s federal certification label/tire placard for vehicles 10000# and above are described in paragraph S5.3.1 in the reference provided below.

tire press ref

FastEagle

FE that still does not explain I what I noted about the difference between Cardinal's and Montana's tire pressure on very similar trailers built is the same time frame. It is not as black and white as you try to make it!

You also have stated that corrections can be made to placard if requested. I tried to get Cardinal to update my weight to the optional 16" LT tires that my trailer had OEM, and they said they would not do that, that the GAWR and GVWR weight was based on the 15" ST tires and they would not issue a new placard. So my 5200 pound axles are derated to 5080 pounds. Tires are listed as LT235/85R16E. So they refused to change from the tire being the weakest link to the axle being the weakest link.

What do I do? NOTHING! No where on the placard does it state that it most be left in place. In fact on a lot of older trailers they fade out and become unreadable anyway!

People that follow your post know that you grabbed hold of this placard thing as one of your tools to keep people on a particular tire type several years ago, and will not let go of it.

Chris
JIMNLIN
Explorer III
Jan 22, 2014
FastEagle wrote:
Recommended tire pressures must be set by the vehicle manufacturer. Positive direction to set those recommended tire pressures found on your trailer’s federal certification label/tire placard for vehicles 10000# and above are described in paragraph S5.3.1 in the reference provided below.

tire press ref

FastEagle

Yep. more pressure recommendation numbers only. Everyone knows the tire placard is fed mandated to be on the vehicle per 571 FMVSS. And we also know the information on the placard is a recommendation only.

We also know many vehicles out here don't have a tire placard.

We also know a forum(s) with dozens/hundreds of experienced trailer owners who have hundreds of thousands of miles towing a trailer is the best source for finding what worked the best vs a tire or vehicle manufacturers "recommendations" and especially the tire placard recommendations.
FastEagle
Explorer
Jan 21, 2014
Recommended tire pressures must be set by the vehicle manufacturer. Positive direction to set those recommended tire pressures found on your trailer’s federal certification label/tire placard for vehicles 10000# and above are described in paragraph S5.3.1 in the reference provided below.

tire press ref

FastEagle
FastEagle
Explorer
Jan 21, 2014
FastEagle wrote:
JIMNLIN wrote:

Recommended pressures wording on the placard does not mean "the correct" pressure. Its simply the vehicle mfg recommendation as required by the the FMVSS. Its simply a guideline for the owners that isn't sure or have the necessary experience to determine the best tire or pressure for the job. Same with a minimum pressure chart.

I'm glad you used a Safecar reference because it gives this one more validity. (paragraph 3).

Safecar Ref

FE
FastEagle
Explorer
Jan 21, 2014
JIMNLIN wrote:

Sorry, wrong tab selected.

FE
JIMNLIN
Explorer III
Jan 21, 2014
The tire placard and the pressures listed are a recommendation only and may or may not be the correct pressures for the job.

Recommended pressures wording on the placard does not mean "the correct" pressure. Its simply the vehicle mfg recommendation as required by the the FMVSS. Its simply a guideline for the owners that isn't sure or have the necessary experience to determine the best tire or pressure for the job. Same with a minimum pressure chart.

IMO the tire placard is not the holy grail as a few seem to think. NHTSA says this about the placard. Note; wording like "a information label" and "recommendation".

safecar.gov

Frequently Asked Questions (FAQs)
1. What is a tire “placard?” And where is it usually located?

A tire placard is really just a fancy name for a tire information label. This label contains several key pieces of information: (1) the vehicle manufacturer’s recommended psi (pounds per square inch) or kilopascals (kPa) of air pressure for your vehicle’s tires, (2) the maximum weight (or “load”) you should have in your vehicle. Load or weight limits are usually given in terms of number of occupants or total weight (in pounds or kilograms) and (3) the recommended tire size."

Never heard of derating a tire on a trailer with those minimum pressure charts till the last few years. IMO not the best choice.... for tires on a trailer.

Forum Discussion

tire air pressure

36 Replies

About Fifth Wheel Group

Related Content

Tire Pressure?

Tire pressures

Tire pressures

Maintaining air pressure in your tires

Air Pressure 19.5 tires