Tire Pressure?

The way you state it Ron , I asume you mean the opposite.
But on purpose I dont come with an advice , because to few data are given, to give propper advice.

jadatis wrote:
Wich 8R19.5 tires do you have from the list, is it the E-load with 80 psi AT-pressure or the D-load with 70psi AT-pressure?
strange is that the D load has lower loadcapacity for the 70 psi pressure then the E-load , what would be expected is higher.
Best is to look at the sidewall for the right maximum load and loadkind, and try to determine the maximum speed of tire.
Mostly give as letter and I think for these sises it will be 75m/120km/h, wich is Speedcode L, N = 140km/87m/h.

Checked the calculation and was done with using power 0.7 for the E-load and even as low as 0.65 for the D-load in the list of the picture you gave.
This is what is done in America and is wrong ( I dare to state).
Europe uses for all kind of tires 0.8 power and the higher the power to 1 , the lower loadcapacity for the pressure .

Will give text I used for other topics with the data I need to calculate it for you . Can be off topic a bit , and some data you already gave ( GAWR's ). In spreadsheet I will use , I use my own determined formula that is to my conclusion closest to the ever to be constructed ideal formula to laws of nature, wich are the same over the world, and using this you can even go as low as zero pressure if the load is low enaugh.

Tirepressure advice is all about load on tire and speed ( and sometimes about alighnment - camber angle).

So if you can give details of car and tires , I can calculate an advice pressure with some reserve for things like, pressure-loss in time, unequall loading R/L, incidental extra load, misreadings of pressure scales,and misyudging of weight, etc.

This is from tires next and can be read from sidewall:
Maximum load or loadindex.
Kind of tire to determine the AT-pressure/pressure needed for the maximum load up to maximum speed of tire, or if lower 160km/99m/h/reference-pressure, wich is not the maximum pressure of tire.
Maximum speed of tire, most given as letter ( Q=160km/99m/h,N=140km/86m/h fi)
If you have offroad or tires looking like that , with large profile blocs that cover a part of sidewall, also mention, they are allowed lesser deflection then a normal road tire, then the tire maker used to determine the maximum load (to my conclusion the case for the Bridgestone tires on Ford Explorer in the Ford/Firestone affaire).
If you cant find all of it give sises of tire and Loadkind, then I will google for it.

From car next and mostly can be found on same plate as the original pressure advices:
GAWR and GVWR ( Gross Axle/Vehicle Weight Rating)
But best would be to determine the real weights in your use on seperate tires or estimate it as acurate as possible, by weighing per wheel(pair) or axle.
Maximum speed , you dont go over for even a minute in your use, eventually different for different situations, for instance when towing or fully loaded.This apart from trafic regulations, if you drive faster then allowed give that speed. Nature punnisches with tire-failure, police only with a penalty.

Whew! Well that explains it clearly. :S

Ron

lanerd wrote:
First, you really need to take your mh to some scales and have it weighed. That is the only way you can accurately determine how much pressure is required.

I assume that the part of the chart don't you understand is because you are looking for the max weight on the chart that the chart doesn't show.

Weigh the rig and then look on the chart for those weights on the chart. The front tires will use the "Radial Tires Used As Singles" with the top figure being lbs and the bottom figure being kgs.

When you weigh the rig, you will probably only be able to weigh each axle, and if this is the case then the rear tires will use the "Radial tires Used As Duals" (top figure lbs, bottom kgs) and you will have to divide the entire axle weight by 4 to get individual weights.

Hope this makes sense. In any case, the chart is only good if you weigh the rig...it's not marked for max weights.

Ron

X2 - weigh your rig loaded for travel. Otherwise you have no starting point to reference the chart. The sticker in the MH is often wrong.

Wich 8R19.5 tires do you have from the list, is it the E-load with 80 psi AT-pressure or the D-load with 70psi AT-pressure?
strange is that the D load has lower loadcapacity for the 70 psi pressure then the E-load , what would be expected is higher.
Best is to look at the sidewall for the right maximum load and loadkind, and try to determine the maximum speed of tire.
Mostly give as letter and I think for these sises it will be 75m/120km/h, wich is Speedcode L, N = 140km/87m/h.

Checked the calculation and was done with using power 0.7 for the E-load and even as low as 0.65 for the D-load in the list of the picture you gave.
This is what is done in America and is wrong ( I dare to state).
Europe uses for all kind of tires 0.8 power and the higher the power to 1 , the lower loadcapacity for the pressure .

Will give text I used for other topics with the data I need to calculate it for you . Can be off topic a bit , and some data you already gave ( GAWR's ). In spreadsheet I will use , I use my own determined formula that is to my conclusion closest to the ever to be constructed ideal formula to laws of nature, wich are the same over the world, and using this you can even go as low as zero pressure if the load is low enaugh.

Tirepressure advice is all about load on tire and speed ( and sometimes about alighnment - camber angle).

So if you can give details of car and tires , I can calculate an advice pressure with some reserve for things like, pressure-loss in time, unequall loading R/L, incidental extra load, misreadings of pressure scales,and misyudging of weight, etc.

This is from tires next and can be read from sidewall:
Maximum load or loadindex.
Kind of tire to determine the AT-pressure/pressure needed for the maximum load up to maximum speed of tire, or if lower 160km/99m/h/reference-pressure, wich is not the maximum pressure of tire.
Maximum speed of tire, most given as letter ( Q=160km/99m/h,N=140km/86m/h fi)
If you have offroad or tires looking like that , with large profile blocs that cover a part of sidewall, also mention, they are allowed lesser deflection then a normal road tire, then the tire maker used to determine the maximum load (to my conclusion the case for the Bridgestone tires on Ford Explorer in the Ford/Firestone affaire).
If you cant find all of it give sises of tire and Loadkind, then I will google for it.

From car next and mostly can be found on same plate as the original pressure advices:
GAWR and GVWR ( Gross Axle/Vehicle Weight Rating)
But best would be to determine the real weights in your use on seperate tires or estimate it as acurate as possible, by weighing per wheel(pair) or axle.
Maximum speed , you dont go over for even a minute in your use, eventually different for different situations, for instance when towing or fully loaded.This apart from trafic regulations, if you drive faster then allowed give that speed. Nature punnisches with tire-failure, police only with a penalty.

First, you really need to take your mh to some scales and have it weighed. That is the only way you can accurately determine how much pressure is required.

I assume that the part of the chart don't you understand is because you are looking for the max weight on the chart that the chart doesn't show.

Weigh the rig and then look on the chart for those weights on the chart. The front tires will use the "Radial Tires Used As Singles" with the top figure being lbs and the bottom figure being kgs.

When you weigh the rig, you will probably only be able to weigh each axle, and if this is the case then the rear tires will use the "Radial tires Used As Duals" (top figure lbs, bottom kgs) and you will have to divide the entire axle weight by 4 to get individual weights.

Hope this makes sense. In any case, the chart is only good if you weigh the rig...it's not marked for max weights.

Ron

Ivylog wrote:
Round the 3900 up to 4000 and divide by two tires... 2000 lbs/tire single so 55 psi for up to 2110/tire.

Round 6300 to 6400 and divide by four tires... 1600 lbs/tire dual so 45 psi for up to 1850/tire.

Not sure why you can go with a lower minimum pressure when dual of 45 psi, but single the minimum is 55 psi. It would be worth the $10 to weigh your axles at a truck stop to make sure you are not over your axle weights.

I suspected that I needed to divide by the number of tires but wanted to be sure. Thanks!

I should have it weighed - I passed up an opportunity on the way to NASCAR this past weekend because I was in a hurry. I need to do it so I can get proper front springs.

Round the 3900 up to 4000 and divide by two tires... 2000 lbs/tire single so 55 psi for up to 2110/tire.

Round 6300 to 6400 and divide by four tires... 1600 lbs/tire dual so 45 psi for up to 1850/tire.

Not sure why you can go with a lower minimum pressure when dual of 45 psi, but single the minimum is 55 psi. It would be worth the $10 to weigh your axles at a truck stop to make sure you are not over your axle weights.