Tire Pressures?

[keigm]

    I just had my 2014 Newmar Mountain Aire weighed.  Now I need an expert inform me the correct tire pressure.  I had 120 of 150 gals of fuel on board and 30 of 105 gals of water on board.  

My Gross Weight was: 40,060 lbs

The Steer Axle was: 15,640 lbs

      Drive Axle was:    20,100 lbs

     Tag Axle:                 4,320 lbs

    It was too bad I wasn't being filmed for candid camera as It took about 5 times to check in with the young lady behind the desk at the Flying J Truck Stop west of Albuquerque.  My 1st attempt was me getting on the scales the wrong way and it went downhill from there.  After the 5th attempt I got the weight, I hope.  Here are manufacture's Numbers:

                          GVWR is:  44,600 lbs

                          Front GAWR:  17,000 lbs

                         Rear GAWR:  20,000 lbs

                         Tag GAWR: 10,000 lbs

                          UVW:     38,400 lbs

[BillAdams]

What you are missing is the weight of each tire.  Your steer axle might be 7,000 on the right and 8,640 on the left.  If so, you have to adjust both tires to the 8,640 rating.  You can make a WAG at the tire pressure requirements by dividing by 2 but it is just that, a guess.  It appears your drive axle is already over loaded and some adjustment to the tag axle (under loaded) may be necessary  to take some weight of the drives.  You can't really be sure where you stand until you can find someone to do a 4 point weighing.

[wolfe10]

Actually the FIRST place to look is weight/ride height on the tag axle.  It is WAY UNDER-loaded, drive is OVER-loaded, and you have spare capacity on the steer axle.

Ideal is to have the same percent of GAWR on each axle.

This will help with handling and ride as well.

Check with your chassis maker for the "how to do".

[jleamont]

I can imagine what you went through and I have to admit I got to laughing 

I'm with Brett, put more on the tag, sounds like you will be back at the scales.

[keigm]

Thanks for the help.  

[tireman9]

After you get the weight more evenly distributed (by % GAWR) you can then look up the MINIMUM cold inflation pressure needed for the tires on each axle.

If you don't get the individual corner weights I suggest you be conservative and figure 53% on one side. Use that number to consult inflation tables for the MINIMUM inflation. 

Set your TPMS warning to the MINIMUM inflation number    I then suggest you add 10% to give you a nice margin for establishing the CIP.