Tire Pressure

Say what and all this about one properly inflating his tires before starting out?
By now, the OP is probably long gone!

TNGW1500SE wrote:
I'll start an argument:

Fill them with NITROGEN!

Pressure will not change as much due to temperature fluctuation.

Nitrogen is an other discussion, I thought I was complicating discussions to much , but you now do.

But OK.. Any gas compound that stays gas in the temperature range of tires inside ( so not water, and Butane) gives same pressure-chanche for temperature-chanche. So my made list in former post,also goes for Nitrogen filled tires.

Additional : My calculation assumes no vullume change by other pressure in tire, wich it will be for an already pressurised tire.

Effy wrote:

Tom/Barb wrote:

becker wrote:
Question: Presently in Albuquerque.... came in from Houston, tx....getting ready to proceed to St.George,Az.... all tires are about 5 lbs low.... how does temperature and altitude affect tire pressure as I proceed North.... do I need to fill the tires back to normal traveling pressure every morning before I get on the road? Thanks

5 pounds low..... lower than what?

Here is a second method of determining the correct pressure for the tire vs the load being carried.

at each stop during the day check each tire for being hot. if you find a tire hotter than the others, raise the pressure 10 pounds. when they are all hot raise them all.

While I agree that a hot tire can be one indication of under inflation, define hot. It's not something you can readily tell by touch. And if you have a thermal gauge, what's the temp to indicate an issue? 110, 120, 130? And blindly adding 10 psi to each tire, especially a hot tire might not be the answer. Suppose that tire was on the sun side, or on the lower crown side of the road, or the side weight is being pushed to by the wind, or there is a brake dragging issue. Any myriad of things that should not be resolved by blindly adding 10 psi.

The overarching answer to how to set proper psi on any tire for any condition, is to weigh your rig loaded for travel, and set the psi - cold- to the tire manufacturers chart. Cold meaning prior to driving, despite whatever the ambient temperature is. Cold does not mean after you drove for a while, after you rested for a while, adding psi for ambient temp etc. Cold means before you drive on them. Not sure why this always gets over complicated. Fluctuations in ambient temp as well as altitude are already accommodated for by design of the tire - provided it is weighed and set correctly to the chart. Don't over think it and borrow trouble. If you set it cold per the chart before you leave, it will be fine by the time you get to wherever you are going. Of course a good TPMS is always a good idea to keep an eye on things.

any tire running different than the others as an inflation problem. All tires on the coach should be simply warm, not hot to the touch, extreme heat will melt the rubber and cause the tire to fail.

read the tire, it will talk to you, all the new technology will only tell you what a simple touch can.

IMO, Effy is correct. Many people overthink this issue and then their brains freeze up and they end up doing barely anything.

First thing is to either buy a truckers air pressure gauge, or go to a truck tire shop and get your tire pressures checked. Find somewhere nearby that shop if you've driven over 4 miles to just sit and wait a couple hours for the tires to cool down. Then drive to the tire shop.

Have them set them to the max pressure listed on the side wall. After you've done that, than you should...

Get the rig weighed. Either pay for it, or do it for free at a closed weigh station along a freeway. With that knowledge, check what the tire manufacturer suggests as the appropriate PSI. Note that when you weigh the rig, if you get 4 corner weights, the tire pressure is set for the highest weight across the axle. So all tires across the axle are the same PSI.

As long as the tire pressures are not too low or too high, you have quite a while, and many happy miles of driving, before any safety or wear issues will show up. And that's all proper pressure is about, maximizing safety and longevity.

Lwiddis wrote:
NITROGEN is for drinking. Not tires.

Nitrogen is for keeping Guinness foamy, and for use in drag slicks. The motorhome and the trailer tires have just plain old air in them even though we carry nitrogen in the trailer and it would possibly be easier to use the nitrogen bottle than to fire up the air compressor and drag out the hose.

Got a Tire Minder TPMS which makes it really easy to check the tire pressures in the AM while DW is getting things ready for travel.

NITROGEN is for drinking. Not tires.

:) Fill with 78 percent nitrogen, 21 percent oxygen, and 1 percent other gasses mixture. I will sell you this special mix cheap but you must buy a years supply with a credit card and sign a multi year contract. ;)

TNGW1500SE wrote:
I'll start an argument:

Fill them with NITROGEN!

Pressure will not change as much due to temperature fluctuation.

:S

I'll start an argument:

Fill them with NITROGEN!

Pressure will not change as much due to temperature fluctuation.

Tom/Barb wrote:

becker wrote:
Question: Presently in Albuquerque.... came in from Houston, tx....getting ready to proceed to St.George,Az.... all tires are about 5 lbs low.... how does temperature and altitude affect tire pressure as I proceed North.... do I need to fill the tires back to normal traveling pressure every morning before I get on the road? Thanks

5 pounds low..... lower than what?

Here is a second method of determining the correct pressure for the tire vs the load being carried.

at each stop during the day check each tire for being hot. if you find a tire hotter than the others, raise the pressure 10 pounds. when they are all hot raise them all.

While I agree that a hot tire can be one indication of under inflation, define hot. It's not something you can readily tell by touch. And if you have a thermal gauge, what's the temp to indicate an issue? 110, 120, 130? And blindly adding 10 psi to each tire, especially a hot tire might not be the answer. Suppose that tire was on the sun side, or on the lower crown side of the road, or the side weight is being pushed to by the wind, or there is a brake dragging issue. Any myriad of things that should not be resolved by blindly adding 10 psi.

The overarching answer to how to set proper psi on any tire for any condition, is to weigh your rig loaded for travel, and set the psi - cold- to the tire manufacturers chart. Cold meaning prior to driving, despite whatever the ambient temperature is. Cold does not mean after you drove for a while, after you rested for a while, adding psi for ambient temp etc. Cold means before you drive on them. Not sure why this always gets over complicated. Fluctuations in ambient temp as well as altitude are already accommodated for by design of the tire - provided it is weighed and set correctly to the chart. Don't over think it and borrow trouble. If you set it cold per the chart before you leave, it will be fine by the time you get to wherever you are going. Of course a good TPMS is always a good idea to keep an eye on things.