Tire pressure ?

[johnythunder]

i'm have a debate with my son in law.on travel trailer tire inflation the tire says maintain 65 psi.he says go lower for temp fluctuation.i say maintain means to keep it at 65 psi all the time. who's right

[ByeTheWay]

I'm sure the engineers who designed the tire considered temp fluctuation

[jrollf]

Do not reduce tire pressure to "account for tire temperature fluctuation". This is why it is the "cold inflation" pressure. You set your pressure when the tire is cool. The tire is designed to work with the pressure increase due to temp.

Here is a great blog/website, written by a tire engineer, not internet know it alls.

https://www.rvtiresafety.net/

[rkresge]

Originally Posted by johnythunder

i'm have a debate with my son in law.on travel trailer tire inflation the tire says maintain 65 psi.he says go lower for temp fluctuation.i say maintain means to keep it at 65 psi all the time. who's right

I'm I'm understanding what you're saying, I'm pretty sure neither one of you is right. Tire pressure should be set when the tires are "cold", before they are warmed up by driving. Also before sun hits. "Cold" means current ambient temperature, whether it's 40 or 90. Your tire pressures will rise as you drive, but the manufacturer has designed for that, so you don't adjust through the day to maintain as you suggest.


Think about that. You drive for an hour, and your pressure goes up to 70, so you stop and reduce the pressure back to 65. What happens overnight when the tires cool down to ambient temperature? Now you'll have to add air in the morning to get back to the 65 lb 'cold' pressure. Not where you want to be.



Good luck,


Roger

[Jay D.]

i allways run them at the max stated on the tire its self.
question what do tire pressures do when you go from sea-level to 6000' elevation? look at a bag of potato chip bought at sea level and then at 6000'. the bag will be about ready to explode, look like a over inflated beach ball.
Jay D.

[jrollf]

Originally Posted by Jay D.

i allways run them at the max stated on the tire its self.

question what do tire pressures do when you go from sea-level to 6000' elevation? look at a bag of potato chip bought at sea level and then at 6000'. the bag will be about ready to explode, look like a over inflated beach ball.

Jay D.

Climbing from sea level to 6,000 ft produces a tire pressure increase of 3 psi... not much to worry about... Sea level to 10,000 ft increases tire pressure by 4.6 psi. And because it is generally colder at higher altitudes, often the tire pressure increase is even less.

https://m.tirerack.com/tires/tiretec...jsp?techid=167

"This means that in many cases differences in ambient temperature may come close to offsetting the differences due to the change in altitude. Depending on the length of their stay at different altitudes, drivers may want to simply set their cold tire pressures the morning after arriving at their destination, as well as reset them the morning after they return home."

[Podivin]

Your son is wrong for sure.
I think you might be tripping up on the word 'maintain' - if that's what it says where you're reading. You don't try to get the tire to hold (maintain) 65 psi all through the day. You inflate to 65 psi before you start to travel for the day, and then don't check it again that day (unless you have a specific reason to think there is an issue).

Personally I check the tire inflation on my RV every couple of months, same as I do on my cars. I have a TPMS that is always on when travelling so that I know if a tire goes below a set psi, other than that I just don't worry about them. My RV rarely sits for more than a few weeks at a time, and then it's sitting in my driveway. If I drove it less or it was stored somewhere farther away then I might check the tires every time before I drove it out of the storage lot.

[tuffr2]

I would set the pressure to what the tire says for 'cold pressure'.

[Jay D.]

Originally Posted by jrollf

Climbing from sea level to 6,000 ft produces a tire pressure increase of 3 psi... not much to worry about... Sea level to 10,000 ft increases tire pressure by 4.6 psi. And because it is generally colder at higher altitudes, often the tire pressure increase is even less.

https://m.tirerack.com/tires/tiretec...jsp?techid=167

"This means that in many cases differences in ambient temperature may come close to offsetting the differences due to the change in altitude. Depending on the length of their stay at different altitudes, drivers may want to simply set their cold tire pressures the morning after arriving at their destination, as well as reset them the morning after they return home."

THANKS
Jay D.

[Skilletface]

Originally Posted by johnythunder

i'm have a debate with my son in law.on travel trailer tire inflation the tire says maintain 65 psi.he says go lower for temp fluctuation.i say maintain means to keep it at 65 psi all the time. who's right

Both may be correct in your debate!
In order solve this both of you need to understand how much weight is actually coming to bare on the axel or axels and divide by 2 or 4 . This can be accomplished at any public scale.

Many people skip over the part stamped on the sidewall where it is stated what the Max Weight is and go straight to Max. Cold inflation.
That’s not necessarily a bad thing, however, if the tire does not run with with the Max. Load then Max. Cold inflation is not required.
Unless your are trying to compensate for trailer sway and even then it won’t help much; there are other weight distribution issues in play.

Checkout the link below for guidance by Manufacture or Tire size, after viewing the charts the recommended inflation might seem low. Most people will add 10-15% more just for piece of mind.

Ever notice how tires sometimes wear out in the middle leaving good tread on the outside, this indicates over inflation and approximately only 60% of the tire is making contact with the road surface.

Simple visual verification method:
Get your unit axled out and adjust cargo inside if necessary, using a gallon of water make the ground wet in front of your tires and pull through the wet spot, observe how the tread face of the tire is contacting the ground it should appear darker than the sidewall, make 2-5 psi adjustments up or down if required, until a nice even wear appears on the tread face.


https://tirepressure.com/

[timetogo]

Low air pressure increases heat and heat kills tires. I run max psi stated on TT sidewalls.

[Jaynelson]

I have a very scientific system where I get the max PSI off the tire, knock 5-10 PSI off that (makes for a slightly smoother ride on rough roads, in my head at least) and ruuuun em.

If I was driving freeways/higher speeds I would just run the max as stated on the sidewall

[JIMNLIN]

Originally Posted by johnythunder

i'm have a debate with my son in law.on travel trailer tire inflation the tire says maintain 65 psi.he says go lower for temp fluctuation.i say maintain means to keep it at 65 psi all the time. who's right

Lots of misinfo about tires on a trailer on rv websites.https://www.rvtiresafety.net/2012/09...-increase.html
Use this from Tireman9 (Roger Marble) who is a actual tire engineer. He separates lots of mis info we see posted even on this thread from tire facts. Lots of tire tech info about tires used in a trailer position vs same tires used on our trucks...motorhomes...suvs/etc. Hours of reading on tire subject for each type of rv vehicles.

The way you worded your question with the word "maintain" you both may have missed what tire mfg say on the psi subject.
Tire engineers/mfg says cold set your tires pressure which most folks do in the morning before the sun shine on them. They also know a load carrying tire gains heat at highway speeds . Heat increases the tires pressure which is normal tire operation.
They also warn not to let air out of a hot tire.

I've seen my 16" LT E 80 psi (cold set to that psi) tires on my equipment trailer/trucks go to 94 psi on a hot day with close to max loads at highway speeds. Next morning on my pre check the tires were back to normal 80 psi.

Now if you want to "maintain" that 65 psi 24/7 then nothing wrong with doing so. But your gonna need to add a lot of air to cold set and stop continually all day long let air out of your tires.

[TexasJeff]

I'm not coming from a point of knowledge here so I want to ask more for clarification of my understanding than anything.

I had always thought that the inflation information on the sides of the tires were "maximum" cold tire pressure. Shouldn't you adjust your tire pressure to make sure your tire's wear is even across the tread but never exceeding that maximum pressure? Or does this line of thought only apply to passenger tires?